Raonic was born on December 27, 1990, in Titograd, SFR Yugoslavia (now Podgorica, Montenegro), and is of Serb heritage. Prompted by the political unrest in the Balkans, and seeking more professional opportunities, his family moved to Canada in 1994 when he was three, settling in Brampton, Ontario, a northwest suburb of Toronto. His parents are both engineers; his father, Dušan, holds a Ph.D. in electrical engineering, while his mother, Vesna, has degrees in mechanical and computer engineering, including a master’s. He has two siblings, both significantly older: his sister, Jelena, has a master’s degree in international trade and finance and is eleven years older, while his brother, Momir, has a degree in information technology and business and is nine years older. Raonic’s uncle, Branimir Gvozdenović, is a politician in the Government of Montenegro, where he has served as Deputy Prime Minister. Raonic is fluent in Serbian and English.

At the US Open, Raonic was seeded fifth. He won his first three matches to face rival Nishikori in the fourth round. On the morning of September 2, Raonic and Nishikori tied the all-time latest finish for a match at the US Open, ending at 2:26 a.m. This tied previous matches between Mats Wilander and Mikael Pernfors in 1993, and between Isner and Philipp Kohlschreiber in 2012. The five set match lasted 4 hours and 19 minutes, with Raonic losing and Nishikori advancing to the quarterfinals. In October, Raonic reached the final of the Japan Open for the third consecutive year, but lost to Nishikori again.

Two weeks later, Raonic won his first ATP title at the Pacific Coast Championships, with victories over No. 45 Xavier Malisse, No. 170 James Blake, No. 74 Ričardas Berankis, and No. 9 Fernando Verdasco. With the victory, he became the first player born in the 1990s to win an ATP title, and the youngest winner since Marin Čilić won the 2008 Connecticut Open at age 19. Raonic’s victory was the first ATP title by a Canadian since Greg Rusedski in 1995.

Raonic first competed at a junior event sanctioned by the International Tennis Federation (ITF) in October 2003 at the age of 12. Two years later, in October 2005, he picked up his first singles match victory at age 14. His first juniors titles in both singles and doubles came at the same Grade 4 tournament in October 2006. Later that year, he won the Prince Cup doubles title, partnering fellow Canadian Vasek Pospisil for the first time at an ITF event. Pospisil and Raonic partnered at four more junior tournaments, including the 2008 Wimbledon Championships and the 2008 French Open, reaching the semifinals in the latter. His most notable titles as a junior were in doubles, winning two Grade 1 events in 2008 partnered with Bradley Klahn.

While an amateur, Raonic played in fourteen professional tournaments against adults in North America: ten ITF Futures events at the bottom tier of professional tennis; three ATP Challenger Tour events at the middle tier; and one ATP World Tour event at the top tier. He played his first professional circuit match in the qualifying draw of an ITF Futures tournament in Toronto in October 2005 at the age of 14; he won his first professional circuit main draw match at an ITF Futures tournament in Gatineau, Quebec, in March 2007 against Fabrice Martin. With the win, Raonic earned his first world ranking of No. 1518. He played his first professional circuit doubles match at the same tournament, partnered with Pospisil again. Raonic lost his first ATP Challenger Tour match in Granby, Quebec, in July 2007 against Gary Lugassy. Raonic won his first ITF Futures doubles title in Gatineau, Quebec in March 2008, and reached his first ITF Futures singles final two weeks later in Sherbrooke, Quebec. He received a wildcard to the qualifying tournament of the 2008 Canadian Open, but lost in the first round to Alexander Kudryavtsev. The match was his first in the ATP World Tour.

Raonic and Curtis worked together “twice a day, almost every day, for the next nine years.” Provided that he complete his courses, Raonic was allowed to reduce his hours of attendance at Thornhill Elementary School so that he could practise more, which he did both before and after school. His parents and siblings supported his tennis, taking turns driving him to practice and tournaments, but did not push him to it or interfere with coaching. Rather, they emphasized school throughout, insisting that he maintain academic excellence as a prerequisite to playing tennis. He attended Thornhill Secondary School, and accelerated his course load—achieving an 82 percent average—so that he could graduate a year early. Late in 2007, at the age of 16, Raonic moved to Montreal as one of the first group of players at Tennis Canada’s new National Tennis Centre, thus marking the end of his formal relationship with Curtis.

After turning professional in September 2008 until the end of 2010, Raonic played both singles and doubles, primarily at ITF Futures and ATP Challenger tournaments. He won his first ITF Futures singles title in March 2009 in Montreal. He added three more singles titles and five doubles titles at the ITF Futures level in 2009 and 2010. He was less successful at the ATP Challenger level, tallying only one title. In his fourth tournament after turning professional, Raonic won the doubles title at the Men’s Rimouski Challenger in November 2008, partnered with Pospisil.

At the ATP World Tour level, Raonic gained entry into few tournaments, compiling a main draw record of three wins and five losses over nearly two and half years. In 2009, Raonic again received a wildcard for the qualifying tournament of the Canadian Open. This time, he beat No. 77 Teymuraz Gabashvili and No. 113 Michaël Llodra to qualify for the main draw of an ATP World Tour tournament for the first time. In the first round, he held a match point, but lost to No. 10 Fernando González in three sets. The matches against Gabashvili and González were the first singles matches for Raonic against a top 100 player and top 10 player, respectively.

Raonic’s coaching relationship evolved during his early professional years. Since late 2007, Raonic had been working with Tennis Canada coaches—including Guillaume Marx, Head Boys National Coach—based out of the National Training Centre at Jarry Park in Montreal. In November 2009, with Raonic’s world ranking at No. 377, Tennis Canada hired recently retired former player Frédéric Niemeyer to coach Raonic and travel with him for 18 weeks during the 2010 season. Toward the end of 2010, however, Niemeyer decided to travel less owing to “family considerations.” As a result, Tennis Canada arranged for a two-week trial period with former No. 40 Galo Blanco in co-operation with Niemeyer, including tournaments in Malaysia and Japan in late September and early October. Over this period, Raonic climbed from No. 237 to No. 155. Tennis Canada hired Blanco, and Raonic moved to Barcelona to train with Blanco and trainer Tony Estalella. Commenting on the training regiment, Blanco said “the off-season Milos had this winter in Barcelona was amazing. We never saw anything like that before, working the way he worked for six weeks.”

Less than a month later, Raonic gained entry into a Grand Slam tournament for the first time at the 2010 US Open. He qualified for the main draw, but lost in the first round to Carsten Ball. Raonic’s first ATP main draw singles victory came in September 2010 at the Malaysian Open against No. 105 Igor Kunitsyn. He followed this with a second round victory over No. 31 Sergiy Stakhovsky. The following week, Raonic lost in the second round of the 2010 Japan Open to No. 1 Nadal. This marked his first singles match against a player ranked No. 1, and his first singles match against a member of the Big Four—a quartet of dominant tennis players including Nadal, Djokovic, Roger Federer, and Andy Murray.

From 2010 to 2016, Canada competed in 16 Davis Cup ties. Raonic represented Canada in 11 of those ties, missing five due to injury: Ecuador in 2011, Japan in 2014, Belgium in 2015, and France and Chile in 2016. Overall, Raonic has 16 match wins in 22 Davis Cup matches (14–5 in singles; 2–1 in doubles). He is one of the most successful players in Canadian Davis Cup history, tied for sixth in match wins overall and for third in singles match wins.

Raonic made his Davis Cup debut in Bogota against Colombia in 2010 at the age of 19. Raonic lost both of his singles matches (against Santiago Giraldo and Juan Sebastián Cabal), but won his doubles match partnered with Nestor, who was then the top ranked doubles player in the world. His first singles match victory came in Canada’s next tie against the Dominican Republic, when he beat Víctor Estrella Burgos in five sets. This marked the first five set match of Raonic’s career. Competing against Mexico in 2011, Raonic won three rubbers in a tie for the first time, beating both Manuel Sánchez and Daniel Garza in singles and partnering with Pospisil to win in doubles as well.

He worked for Rogers Sportsnet as an analyst while recovering from injury for their broadcast of the 2011 Canadian Open. In November 2011, Raonic won an exhibition match against his childhood idol, Pete Sampras, which was dubbed “The Face Off.” In 2012, he took up residence in Monte Carlo, Monaco in a 50 metre (538 sq ft) apartment, located minutes away from the Monte Carlo Country Club—his “home” tennis club and the site of the Monte-Carlo Masters tournament—and Stade Louis II, which he uses for off-court training. Raonic was in a relationship with Canadian model Danielle Knudson.

By the summer of 2008, Raonic had received scholarship offers from several colleges, including the University of Michigan, Princeton, and Northwestern University, and committed to play for the University of Virginia that fall while studying finance. Just two weeks before school started, he consulted his parents about his plan to turn professional instead. Raonic and his parents agreed that he would take correspondence courses in finance from Athabasca University while starting a professional tennis career, setting a deadline of two years for reaching the top 100. During that summer, his world ranking ranged between No. 915 and No. 937. Raonic reached the top 100 in January 2011, around five months later than the target deadline. He thus turned down the scholarships and turned professional, agreeing to be represented by the sports agency SFX. University of Virginia men’s tennis coach Brian Boland later commented that “I have only seen two guys turn down scholarships and then succeed quickly on the Tour: Sam Querrey and Milos Raonic.”

Three years prior, in 2011, Raonic had set a personal goal of reaching the year-end ATP Finals, where only the top eight players earned a spot. Heading into the last ATP 1000 event of 2014, the Paris Masters, Raonic trailed Ferrer for the eighth spot, and needed a deep run to surpass him. He beat Sock and Roberto Bautista Agut to set up a quarterfinals match against No. 2 Federer, who had beaten him in all six previous meetings. Needing a win to avoid being eliminated from contention for the ATP Finals, Raonic won in straight sets. His victory was hailed as “a career-defining win.” In the post-match interview, Raonic was asked to rank this victory in his career. He replied: “Considering all the circumstances around it, I think this was the biggest win for me.” He went on to beat No. 5 Berdych in the semifinals to earn a spot in the second ATP 1000 final of his career. He lost to Djokovic in the final, but secured his place in the 2014 ATP Finals. He is the first Canadian to reach the ATP Finals, and the first player born in the 1990s to do so. Anticlimactically, Raonic withdrew from the tournament due to a leg-muscle tear prior to his match against Nishikori, after losses to Federer and Murray.

In 2011, while recovering from a hip injury sustained at Wimbledon, Raonic decided to become involved with philanthropic work, focusing on helping disadvantaged children. The following year, in 2012, he launched the Milos Raonic Foundation, which aims to “support children from disadvantaged backgrounds in order to remove economic, physical and other barriers that might prevent them from becoming healthy, productive members of society. … In the initial stages of its work, the foundation will focus, in particular, on children with physical disabilities.” As of 2016, the foundation had awarded $120,000 in grants to the Holland Bloorview Kids Rehabilitation Hospital, and $30,000 to the Canadian Paralympic Committee. Raonic and his parents are the three directors of the foundation, which has partnered with ATP Aces for Charity.

Raonic began 2012 with titles in two of his first three tournaments, starting with his second ATP title at the Chennai Open in India. He had back-to-back wins over top 10 players at a tournament for the first time, beating Nicolás Almagro in the semifinals and Janko Tipsarević in the final. Raonic held serve during the entire tournament, becoming the first player to do so since Federer at the 2008 Halle Open. He lost in the third round of the Australian Open to Lleyton Hewitt. In February, Raonic defended his title at the Pacific Coast Championships, defeating Denis Istomin in the final for his third ATP title. The following week in Memphis, Raonic reached the final of the U.S. National Indoor Tennis Championships for the second straight year, but lost to Melzer.

In 2012, Raonic led the ATP in points won on 1st serve (82%) and in service games won (93%). He finished the year at a career high singles ranking of No. 13. His six victories over top 10 players in 2012, including two over Murray, marks a career-high.

Several celebrity fundraising events have been held in conjunction with the foundation. On November 15, 2012, the inaugural “Raonic Race for Kids” was held, with multiple teams competing in quick physical and intellectual challenges. Teams were led by celebrities, including Canadian Football Hall of Fame quarterback Damon Allen and tennis players Eugenie Bouchard and Daniel Nestor. The next night, a second “Face Off” event featured exhibition matches between Raonic and Andy Roddick, and between Serena Williams and Agnieszka Radwańska. In November 2013, the second “Raonic Race for Kids” featured Davis Cup captain Martin Laurendeau, musician Jim Cuddy, and broadcaster George Stroumboulopoulos. The third “Raonic Race for Kids” in November 2014 featured Tennis Canada CEO Kelly Murumets, soccer player Dwayne De Rosario, and figure-skating champions Patrick Chan, Tessa Virtue, and Scott Moir.

In 2013, Raonic again led the ATP in points won on first serve (82%) and in service games won (91%). He had 45 match victories for the second consecutive year. His coaching team underwent significant changes in 2013. In May, Raonic split with his coach of two and half years, Blanco. Less than a month later, Raonic hired former No. 3 tennis player Ivan Ljubičić as his coach. In December, he hired Riccardo Piatti as a co-coach with Ljubičić.

From March through May, Raonic improved on his career-best performance at five consecutive ATP 1000 events. At the Indian Wells Masters, he beat No. 6 Murray to reach the quarterfinals, losing to Alexandr Dolgopolov. He lost in the quarterfinals of the Miami Masters to Nadal. He reached the quarterfinals for the third ATP 1000 tournament in a row at the Monte-Carlo Masters, before falling to Wawrinka. The result garnered Raonic a career-high ranking as world No. 9. Raonic lost in the third round of the Madrid Open to Nishikori. At the Italian Open, Raonic defeated Jérémy Chardy in the quarterfinals to reach his first Masters 1000 semifinal on clay. After winning the first set, he lost his semifinal match to eventual champion Djokovic. Although he had played Djokovic in the 2013 Davis Cup, this was their first ATP match against one another.

In the 2013 Davis Cup World Group first round, Raonic won singles rubbers over Ramos-Viñolas and Guillermo García-López to lead Canada over top-seeded Spain. He repeated this feat with victories over Fabio Fognini and Seppi to help Canada defeat Italy in the quarterfinals, sending Canada into the Davis Cup semifinals for the first time since 1913. In the semifinal against Serbia, Raonic won his singles match over Tipsarević, but lost to No. 1 Djokovic as Canada was eliminated. The defeat marked Raonic’s first singles match against Djokovic.

Raonic endorses the Wilson BLX Blade 98 18×20 tennis racket, and uses LUXILON M2 Pro 1.25 16L strings. In January 2013, Raonic became the first tennis player to endorse New Balance clothing and shoes, in a deal reported to be worth “US$1 million annually over a five-year term.” Roughly two and a half years later, this deal was extended “for the length of [Raonic’s] career and beyond,” and stipulates that New Balance will increase its support of the Milos Raonic Foundation. The lifelong nature of this contract was described by Tennis Canada as “unique.”

Each of Raonic’s deepest runs in significant tournaments (i.e. majors and ATP 1000 tournaments) has ended with a loss to a member of the Big Four: Nadal in the 2013 Canadian Open final, Federer in the 2014 Wimbledon semifinal, Djokovic in the 2014 Paris Masters final, Murray in the 2016 Australian Open semifinal, Djokovic in the 2016 Indian Wells Masters final, Murray in the 2016 Wimbledon final, and Murray in the semifinals of the 2016 ATP World Tour Finals. At majors, Raonic has a 1–8 record against the Big Four, losing the first five matches in straight sets. He has met only one of the four in Davis Cup play: he lost to Djokovic in the 2013 semifinals.

Raonic opened 2014 by reaching the third round of the Australian Open, losing to Grigor Dimitrov. He sustained an ankle injury that kept him out of action for six weeks.

Raonic ended the year at a career-high season-ending ranking of No. 8. He was one of just three players to reach the quarterfinals or better at seven of the nine ATP 1000 tournaments. Raonic finished with a career-high total of 1107 aces in 2014. At the time, this was the fifth highest single-year ace total in history. (It was surpassed by both Ivo Karlović and Isner in 2015.)

In 2014, Raonic partnered with Bouchard to represent Canada in the Hopman Cup. Raonic won two of three singles matches, and paired with Bouchard to win two of three doubles matches. Canada finished in second place in their pool—behind top-seeded Poland—and were eliminated.

When he was twenty, the National Post described Raonic as a “hothead whose on-court demeanour was holding him back.” As he grew older, commentators came to see him as “stoic”, “robotic”, and “emotionless”, with The Daily Telegraph referring to him as “an analytical character who questions everything he does in practice”. In 2014, Raonic explained: “I’m the son of two engineers, so everything is a numbers and calculation game.” In 2016, he added: “I am very systematic in how [I] need to go about things to bring out the best tennis for myself, and maybe that comes off as mechanical and robotic and those kind of things, but I don’t know if I’d ever change that because I feel that’s the way I get the best out of myself when it comes to my tennis.”

Since March 2014, Raonic has donned a sleeve on his right arm while playing. At first, he wore a fisherman’s sleeve to cover a rash he had due to an allergic reaction to massage cream. This was replaced with an athletic compression sleeve, often colour-coordinated with his on-court apparel. The sleeve is worn for comfort, and wearing it became a habit for Raonic. The sleeve has become a distinctive part of Raonic’s image, and has spawned a Twitter account. The motto “Believe in the Sleeve” has become synonymous with Raonic in the media and among Raonic’s fans. Serena Williams described the sleeve as “super cool and different.”

Raonic’s most frequent opponent, either inside or outside the Big Four, is Federer (14 matches). His first victory over Federer in the 2014 Paris Masters quarterfinal was hailed as “a career-defining win.” His second victory over Federer—at the 2016 Brisbane International—was his first in a final against the Big Four. A third victory over Federer—in the 2016 Wimbledon semifinal—marked Raonic’s first victory at a Grand Slam tournament against the Big Four. Raonic referred to his match against Murray at the 2016 ATP World Tour Finals as “the best match [he’s] ever competed in.”

Raonic began 2015 by reaching the final at the Brisbane International after defeating No. 5 Nishikori in three sets, all decided in tiebreaks. He lost to No. 2 Federer in three sets, with Federer recording his 1,000th match win on the professional tour. Later in the month, he reached the quarterfinals of the Australian Open after beating No. 12 Feliciano López. He lost to Djokovic in straight sets.

Raonic embraced his role as Canada’s top singles player, intent on growing the game in Canada. He stated in 2010: “I want to make a difference in Canada with [my career]. I feel if I were to achieve my goals it could make a great difference to the growth of tennis in Canada and help to produce more top players in the future.” Before a Davis Cup tie with Japan in 2015, he said: “I’m here because I want to be here. I don’t have anybody telling me I need to be here. I want to succeed at this event, and I want to succeed representing Canada.”

Kei Nishikori is often cited as Raonic’s primary rival. The two have very different strengths; according to The Globe and Mail, Raonic uses his “size and his serve”, while Nishikori uses his “savvy and speed.” Both are the first from their respective countries to achieve a top 10 ranking, and both have a career-high ranking inside the top 4. In May 2015, they were the two youngest players in the top 10. Nishikori holds a 5–2 advantage in seven close matches, including two wins in the Japan Open final (2012, 2014). Of the twenty-five sets they have played, ten have required a tiebreak. Only one of their matches has been a straight sets victory. Five matches have required the maximum number of sets. One of these was a marathon US Open five-set match that equalled the record for latest finish ever at 2:26 a.m.

Raonic’s four favourite sports teams are FC Barcelona, the Toronto Blue Jays, the Toronto Maple Leafs, and the Toronto Raptors. He played in the 2016 NBA All-Star Celebrity Game held in Toronto.

In late November, Raonic parted ways with both Ljubičić, who had been his coach since June 2013, and Austin Nunn, who had been his media manager for nearly four years. Ljubičić was added to Federer’s coaching team two weeks later. Raonic contacted former No. 1 tennis player Carlos Moyá about a coaching relationship, and they trained together and had discussions during the IPTL events. The relationship was subsequently formalized and on January 1, 2016, Raonic announced that Moyá would join his coaching team alongside Piatti. Raonic said that he chose Moyá for three reasons: “Carlos is very laid back and positive [… and] he communicates well.”

With the transition to hard courts after Wimbledon, Raonic made the quarterfinals of the Canadian Open, losing to Monfils, before falling to Murray for the fifth time in 2016 in the Cincinnati Masters semifinal. Raonic was the fifth seed at the US Open, but lost in the second round to Ryan Harrison, partly due to debilitating cramps. In September, cramps were cited as the reason for Raonic to miss Canada’s Davis Cup tie against Chile. Later that month, Raonic failed to defend his title at the St. Petersburg Open, falling in his opening match to Youzhny. Raonic withdrew from the China Open prior to his semifinal match due to an ankle injury sustained in the quarterfinal. With the result, Raonic qualified for the ATP World Tour Finals for the second time. Raonic suffered another injury, a quadriceps tear, during his quarterfinal match against Jo-Wilfried Tsonga at the Paris Masters and withdrew before his scheduled semifinal against Murray.

At the ATP World Tour Finals, Raonic lost to Djokovic, but beat Monfils and Thiem in round robin play to qualify for his first Tour Finals semifinal. He lost the semifinal match to Murray in 3 hours and 38 minutes, the longest match on the ATP Tour in 2016 and the longest match in World Tour Finals history. Raonic rose to a career-high No. 3, finishing the year behind only Murray and Djokovic. In December, he ended his coaching relationship with Moya, and added former Wimbledon champion Richard Krajicek to his coaching staff alongside Piatti for the 2017 season.

Raonic decided not to play in the 2016 Summer Olympics, citing health concerns and the Zika virus.

Returning from injury at the Miami Open in March, Raonic defeated Viktor Troicki in his opening round but had to withdraw from his next match against qualifier Jared Donaldson, again with the hamstring injury. In May, Raonic advanced to his second final of the season, losing to Marin Čilić in Istanbul. He lost in the fourth round of the French Open to Pablo Carreño Busta in a five-set marathon. At Wimbledon, he made it to the quarterfinals but was defeated by Roger Federer in straight sets. After his run at Wimbledon, he only played two more tournaments, losing in the quarterfinals in Washington, D.C. to Jack Sock and in the second round in Montreal to Adrian Mannarino. He then had to withdraw from various tournaments, including the US Open, due to injury. Raonic returned in October at the Japan Open but had to retire in his second round match against Yūichi Sugita again with an injury. Although he reached two finals in 2017, it was the first time since 2011 that he failed to win at least one title.

Raonic started his 2020 at Qatar open in Doha where he was seeded 4th. However, only in his first match he lost to Corentin Moutet in straight sets. Raonic then participated in 2020 Australian Open where he defeated Stefanos Tsitsipas and Marin Cilic before losing to Novak Djokovic at quarter-final stage in straight sets. In February 2020, Raonic participated in New York Open where he was seeded second, but he lost to Soonwoo Kwon in his first match at the tournament. Days later, he took part in Delray Beach Open and defeated Denis Istomin, Cedrik-Marcel Stebe before losing his semi-final match to Reilly Opelka.

Raonic will be making his World TeamTennis debut in 2020, and will be joining the Orange County Breakers when the WTT season begins July 12 at The Greenbrier.