Schweinsteiger signed with Bayern Munich as a youth team player on 1 July 1998 and rose through the club’s youth sides. A talented youth ski racer, he had to decide between pursuing a professional career in skiing or one in football. Having won the German youth championship in July 2002, Schweinsteiger quickly earned a place in the reserves, producing a string of solid third-division displays. He initially earned a reputation for being a rebel off the pitch, making headlines for the wrong reasons but has since settled down.

During his first appearances in the titular eleven, he played left-back. After just two training sessions with the first team, coach Ottmar Hitzfeld gave Schweinsteiger his debut, at the age of 18, as a late substitute in a UEFA Champions League game against RC Lens in November 2002, and the youngster made an immediate impact, creating a goal for Markus Feulner within minutes. He signed a professional contract the following month and went on to appear in 14 Bundesliga games in 2002–03, helping Bayern to a league and cup double. The next season, he played 26 Bundesliga games. He scored his first Bayern goal against VfL Wolfsburg in September 2003.

Schweinsteiger made his international debut in June 2004 in a friendly against Hungary and earned 121 caps before his retirement from international football in 2016. He was part of the Germany squad for every major tournament from UEFA Euro 2004 until Euro 2016.

He scored his first two international goals on 8 June 2005 against Russia and scored his first goal in a competitive match against Tunisia on 18 June 2005 at the Confederations Cup in Germany. He was called up to the 2006 FIFA World Cup on home soil and shot into prominence at the tournament with his two brilliant long-range strikes in the third-place match against Portugal, which won him the Man of the Match award. The match ended 3–1 with the 21-year-old nearly claiming a hat-trick but his deflected free kick was credited as an own-goal to Armando Petit.

On 15 August 2008, Schweinsteiger scored the first Bundesliga goal of the 2008–09 season. In December 2010, he extended his contract with Bayern until 2016.

During Euro 2008 qualifiers, he scored two goals en route to a record 13–0 win over San Marino in San Marino. He scored the third goal in Germany’s 4–1 win over Slovakia in Bratislava.

Schweinsteiger featured often in 2010 World Cup qualifying, playing nine of the 10 games and contributing three goals. He started in Germany’s third pre-warm-up game vs. Bosnia on 3 June 2010, and scored two penalties in a 3–1 victory in the space of four minutes, but in the 87th minute he was substituted off for Bayern Munich teammate Toni Kroos.

During the 2010 FIFA World Cup, Schweinsteiger was charged with replacing the injured Michael Ballack at the centre of midfield. He performed admirably in this role, adding valuable leadership and international experience to a very young German side. He was vital to both the German attack and defence, as was apparent when he was named the Man of the Match after the quarter-final match against Argentina, where he provided two assists while also managing to contain Lionel Messi. Germany subsequently lost to Spain in the semi-finals. Germany was able to rally for a 3–2 victory over Uruguay in the third-place match, and, with Philipp Lahm resting on the bench because of illness, Schweinsteiger served as captain.

On 25 April 2012, Schweinsteiger scored from the last and match-clinching penalty kick against Real Madrid to send Bayern through to the 2012 UEFA Champions League Final, where they would face Chelsea. The match, played at Bayern’s Allianz Arena, ended 1–1 and went to a penalty shoot-out. With the shoot-out poised at 3–3, Schweinsteiger’s effort beat Petr Čech but not the post, allowing Didier Drogba to seal the title for Chelsea with the next kick.

In the 2012–13 season, Schweinsteiger performed considerably well, continuing his duties as central midfielder along with new signing Javi Martínez. On 6 April 2013, Schweinsteiger scored a backheel flick goal against Eintracht Frankfurt which sealed the Bundesliga title for Bayern. The season ended on a high for Schweinsteiger, as Bayern secured a treble of Bundesliga, DFB-Pokal and Champions League.

Schweinsteiger made five appearances as Germany qualified for the 2014 FIFA World Cup. On 15 October 2013, he won his 100th cap for the national team in a 5–3 win over Sweden.

Beyond his offensive and creative capabilities, he is also known for his defensive skills, work-rate, and tackling ability. For his performances, he was voted as the best German player of the year in 2013. Jonathan Wilson, when writing for The Guardian during the same year, labelled Schweinsteiger as a type holding midfielder that he described as a “carrier” or “surger,” namely “a player capable of making late runs or carrying the ball at his feet.” During his time with Chicago, Schweinsteiger has also occasionally been deployed as a central defender or sweeper in a three-man back-line, in addition to his usual role in midfield, courtesy of his vision and defensive skills; in this deeper role, he was not only given defensive responsibilities, such as marking opposing players, but was also given offensive duties, and was tasked with playing the ball out from the back, retaining possession, advancing into midfield, and controlling the play. Because of Schweinsteiger’s wide range of skills, his former Chicago Fire manager, Veljko Paunović, described him upon his retirement in 2019 as “unique and special,” also commenting: “He’s a complete player, a total player. In Germany, where they know him even better than us, they call him a ‘Fussballgott’ [a “football god,” in German] because he represents everything.”

In September 2014, he began a relationship with Serbian tennis player Ana Ivanovic. The couple wed on 12 July 2016 in Venice, Italy. The couple have two sons: Luka, born on 17 March 2018 in Chicago, and an unnamed baby born on 30 August 2019.

He made his 2014–15 season debut in a 4–0 win against 1899 Hoffenheim. He came in for Mario Götze in the 78th minute. On 16 May 2015, with Bayern having already won the league, he scored the opening goal in a 2–1 defeat at SC Freiburg. On 23 May 2015, Schweinsteiger scored on his 500th appearance for Bayern. This proved to be his last match with the club. He transferred to Manchester United on 13 July 2015, having been at Bayern for 17 years.

On 13 July 2015, Manchester United completed the signing of Schweinsteiger on a three-year contract for a fee of €9 million (£6.5 million). Manchester United had never before fielded a German in the first team; Markus Neumayr and Ron-Robert Zieler were at the club before him, but neither made it into the first team. Schweinsteiger was given shirt number 23 in pre-season, but switched to 31, which he wore at Bayern, before the official start to the season.

Schweinsteiger made his pre-season debut for Manchester United in a friendly match against Club América on 17 July 2015. United defeated the Mexican club 1–0 in Seattle. His Premier League debut came on 8 August, as a 60th-minute substitute for Michael Carrick as the season began with a 1–0 home victory over Tottenham Hotspur, being booked eight minutes into his first appearance for a foul on Nacer Chadli. On 28 November he scored his first goal for the club, equalising with a header in a 1–1 draw against Leicester City.

On 7 December 2015, Schweinsteiger was punished with a three-match retrospective ban by The Football Association for striking West Ham United’s Winston Reid in the throat in their meeting two days earlier.

After the arrival of new manager, José Mourinho, Schweinsteiger was demoted and sent to training with the under-23 team. A number of high-profile former teammates have criticised Mourinho’s handling of the matter, accusing Mourinho of showing a lack of respect for Schweinsteiger. He returned to first team training towards the end of 2016, and made his first appearance since March when he came on as a late substitute in the EFL Cup quarter-final against West Ham United on 30 November 2016. He made his first start in over a year in a 4–0 win in the FA Cup fourth round home tie against Wigan Athletic on 29 January 2017, in which he scored his first Old Trafford goal for Manchester United with an overhead finish. For his goal, as well as his assist to Marouane Fellaini for the opening goal, he was voted “Man of the Match” by the fans.

Prior to the start of qualification, Schweinsteiger was appointed as the new captain for Germany after Philipp Lahm’s retirement. On 23 March 2016 he sustained damage on his knee while he was training with the German national team which made him miss the rest of the Premier League season but he recovered just in time to be selected for Germany’s 27-man provisional squad for UEFA Euro 2016. On 31 May, Schweinsteiger was selected for Germany’s final 23-man squad for UEFA Euro 2016.

On 12 June 2016, Schweinsteiger scored in stoppage time after coming on late in a 2–0 group stage victory over Ukraine. Nine days later, Schweinsteiger set a new record for German player with the most appearances in a European Championship match. After the tournament, Schweinsteiger announced his retirement from competitive international football, having played in 120 games, scoring 24 goals. One month later, he participated in his last ever international appearance for Germany, against Finland in a friendly match. He was succeeded as captain by Manuel Neuer.

On 21 March 2017, Manchester United allowed Schweinsteiger to join Major League Soccer side Chicago Fire, subject to a medical and a visa being secured. The move was completed on 29 March. A few days later, Mourinho stated that he “regretted” the way he had treated Schweinsteiger. On 1 April, Schweinsteiger debuted for Chicago Fire, scoring in a 2–2 home draw against Montreal Impact. By mid-season, he would help guide Chicago to the top of the MLS standings and be voted into the “MLS All-Star Fan XI” (along with teammate Nemanja Nikolić) to face Real Madrid at the 2017 MLS All-Star Game in Chicago. After guiding the Fire back into the playoffs after a five-year drought, Schweinsteiger was awarded the contract option of another year in 2018. Schweinsteiger netted a goal and also provided an assist to Alan Gordon’s equalising goal in the stoppage time in a 2–2 draw against Toronto FC on 29 April 2018. On 5 August, he scored a long-range goal to level the scoreline after coming on as a substitute in the second half, but his side were defeated in a 2–1 away loss against Real Salt Lake. On 11 July, Schweinsteiger scored a goal in the stoppage time and provided one assist to Aleksandar Katai’s goal in a 4–3 home defeat against Philadelphia Union.

On 8 October 2019, Schweinsteiger announced his retirement from professional football. A few days after his retirement from active sports in October 2019, the ARD announced that Schweinsteiger will be accompanying live broadcasts of football matches as an expert in Qatar for the next three years up to and including the 2022 FIFA World Cup.