Rebecca Quin was born in Limerick on 30 January 1987. She grew up in the Dublin suburb of Baldoyle. Her parents separated when she was one year old. She started watching professional wrestling from a young age with her brother, Richy, who later wrestled under the ring name Gonzo de Mondo. She was involved in horse riding, swimming, and basketball. However, she claimed to have failed P.E. in school.

As a teenager, Quin heard that Fergal Devitt and Paul Tracey were opening a wrestling school in Ireland. She began training there along with her brother in June 2002. She made her professional wrestling debut five months later, using the ring name Rebecca Knox. She teamed with her brother in mixed tag team matches during the early part of her career. She also trained at British professional wrestling promotion NWA UK Hammerlock.

Knox joined the Canadian promotion SuperGirls Wrestling, an all-female offshoot of Extreme Canadian Championship Wrestling (ECCW) in May 2005. Following her arrival at an ECCW show in Surrey, British Columbia, Knox feuded with Miss Chevius and defeated her, but lost to her in Port Coquitlam a month later. The following night, Knox teamed with Calum Macbeth to defeat Miss Chevius and Tony Tisoy in a mixed tag team match in Vancouver. On 24 June, Knox defeated Miss Chevius at an ECCW show in Surrey to become the inaugural SuperGirls Champion. Knox successfully defended the championship on several occasions before eventually losing it to Lisa Moretti in April 2006.

In late 2005, Knox participated in All Pro Wrestling (APW)’s third ChickFight tournament in Hayward, California; she defeated Morgan in the first round, but was eliminated by eventual winner Mariko Yoshida. Knox then won an eighteen-person battle royal at an event in Tokyo, Japan.

Knox began working for the all-female promotion Shimmer Women Athletes in early 2006. In her debut match for the promotion, she defeated Allison Danger, and established herself as a heel (villain) by faking an injury. Following that, she began feuding with Daizee Haze; Knox lost the first match between them, but won the rematch of two-out-of-three falls.

In June 2006, Knox defeated Sweet Saraya to win the vacated World Queens of Chaos Championship at an event in Chouilly, France. She held the championship for few months before dropping it to Saraya in September.

In September 2006, while wrestling in Germany, Knox sustained a legit head injury, following which she claimed to have been “suffering from extremely painful headaches, loud buzzing in her left ear and vision as a result,” and was also diagnosed with possible damage to her eighth cranial nerve. A 60-minute Iron Woman match against Haze at Shimmer’s Volume 7 taping was cancelled as a result.

Following her injury, Quin took a six-year hiatus, wrestling only on three occasions for Irish promotion Fight Factory Pro Wrestling (FFPW) in 2008, 2012 and 2013. She also reappeared in Shimmer in 2011, managing Saraya and Britani Knight for four shows.

During her time away from wrestling, Quin worked as an actress and was cast in numerous plays in 2011 and 2012. She graduated with a degree in acting from the Dublin Institute of Technology, and has attended Columbia College Chicago and the Gaiety School of Acting. She also worked as a flight attendant with Aer Lingus for two and a half years.

In April 2013, Quin signed a two-year developmental deal with World Wrestling Entertainment (WWE) and moved to Florida to report to their developmental territory NXT. On 29 August, her new ring name was revealed as Becky Lynch.

Lynch made her televised in-ring debut on 26 June 2014 episode of NXT, defeating Summer Rae. The next week, Lynch teamed up with Bayley in a losing effort to the BFFs: Beautiful Fierce Females (NXT Women’s Champion Charlotte and Sasha Banks) in a tag-team match. Lynch spent the next few months competing in non-title matches against Charlotte, losing three in a row. On 23 October episode of NXT, after being told to make herself relevant, Lynch aligned herself with Banks by attacking Bayley, turning heel. Known as Team B.A.E. (Best at Everything), the alliance started to disintegrate when Banks cost Lynch a match against Bayley in February 2015.

On 30 November episode of Raw, Charlotte started displaying villainous traits after she feigned a leg injury to defeat Lynch, followed by a distraction provided by her father. Throughout December, the two’s friendship continued to strain and after Lynch defeated her on 4 January 2016 episode of Raw, Charlotte attacked her and solidified her heel turn. Lynch faced Charlotte for the Divas Championship three days later on SmackDown and at the Royal Rumble pay-per-view event, but lost both matches after interference from Ric Flair.

On 11 September, at Backlash, Lynch won a six-pack elimination challenge, last eliminating Carmella, to become the inaugural SmackDown Women’s Champion. Her first title defence against Alexa Bliss was scheduled for No Mercy but due to Lynch suffering a legitimate injury the match was postponed to 8 November episode of SmackDown, where Lynch retained. At Survivor Series later that month, Lynch made up part of Team SmackDown alongside Bliss, Carmella, Naomi and Natalya in a Survivor Series match in a losing effort to Team Raw. At the TLC: Tables, Ladders & Chairs pay-per-view in December, Lynch lost the SmackDown Women’s Championship to Bliss in a tables match, ending her reign at 84 days. She received her championship rematch on 17 January 2017 episode of SmackDown, in a steel cage match but lost after interference from another La Luchadora (later revealed as the returning Mickie James). This led to a match between Lynch and James at Elimination Chamber in February, which Lynch won. Lynch participated in a six-pack challenge for the title at WrestleMania 33 in April, which was ultimately won by Naomi.

Quin performed stunts for a 2013 episode of Vikings. She was written off WWE television for a few months in November 2017 to film The Marine 6: Close Quarters.

In May, Lynch aligned with Naomi and Charlotte Flair against The Welcoming Committee (Natalya, Carmella and Tamina). The two teams faced off in a six-woman tag team match at Backlash; the Welcoming Committee was victorious when Lynch submitted to Natalya’s sharpshooter. Shortly after, Lynch competed at Money in the Bank, as part of the first women’s money in the bank ladder match, which was won by Carmella. In October, Lynch won a fatal five-way match against Flair, Naomi, Tamina and Carmella to become the Team SmackDown’s captain for Survivor Series. At the event, Lynch was the first competitor eliminated and her team was on the losing side. Throughout the rest of the year, Lynch again aligned with Flair and Naomi to feud with the debuting Riott Squad (Ruby Riott, Liv Morgan and Sarah Logan). In January 2018, at the Royal Rumble, Lynch participated in the first women’s Royal Rumble match, entering at number 2 and lasting over 30 minutes before being eliminated by Ruby Riott. A few months later, Lynch also participated in the WrestleMania Women’s Battle Royal at WrestleMania 34, but was eliminated from the match by James. In May, she qualified for the women’s Money in the Bank ladder match, which was ultimately won by Bliss.

Following the 2018 Money in the Bank event, Lynch began a winning streak, defeating different competitors such as Billie Kay, Sonya Deville, Peyton Royce, Mandy Rose, and SmackDown Women’s Champion Carmella in a non-title match. The wins earned Lynch a title match at SummerSlam, with Charlotte Flair being added to the match as well after she also defeated Carmella in a non-title match. Flair went on to win the title by pinning Lynch, who was about to submit Carmella. After the match, Lynch attacked Flair, turning heel for the first time on the main roster. Two days later on SmackDown, Lynch berated the crowd, claiming that they were not really supporting her the whole time, and that she was being denied opportunities which were always handed to Flair. Despite this, audiences increasingly supported Lynch, leading WWE to tweak the storyline and portray both Lynch and Flair as both having valid points, but neither being outright heels.

On 27 January 2019, at the Royal Rumble event, Lynch failed to regain the title from Asuka. Later that night, she participated in the women’s Royal Rumble match, replacing an injured Lana, who was the 28th entrant. Lynch would go on to win with lastly eliminating Charlotte Flair. The following night on Raw, Lynch continued her feud with Ronda Rousey, choosing to face Rousey for the Raw Women’s Championship at WrestleMania 35. As part of a storyline in which she refused to seek medical attention on her knee and attacked Stephanie McMahon and Triple H, Vince McMahon suspended Lynch in February for 60 days and replaced her with Charlotte Flair as Rousey’s WrestleMania opponent. Due to pleadings from Rousey, Lynch was reinstated by Stephanie, and at the Fastlane event, she defeated Flair via disqualification after Rousey purposely attacked Lynch to give her the win; due to the stipulation of the match, Lynch was added back into the title match at WrestleMania to make it a triple-threat match for the Raw Women’s Championship.

She is the first WWE Superstar to ever appear on the cover of ESPN The Magazine, as well as the first-ever female Superstar to feature on the cover of a WWE 2K video game. She holds the record for most PPV shows main evented in one year for a female wrestler (3 in 2019). She became the only woman to win the Pro Wrestling Illustrated’s Most Popular Wrestler of the Year in 2019, Becky was also the first and only female performer in WWE history to lead the company in merchandise sales. Her Last Woman Standing match against Charlotte Flair on WWE Evolution was ranked No. 1 by WWE on “The Top 25 Matches of 2018” list. Lynch’s Raw Women’s Championship match against Sasha Banks on Hell in a Cell 2019 was ranked No. 2 on the same list in 2019.

WWE Hall of Famer Booker T compared Lynch’s rise to The Rock’s and added: “Becky is at the point where she and everybody in the locker room knows how good she is”. Wrestler Toni Storm cited Lynch as her biggest inspiration and said that she is “taking the women’s division to a completely different level.” In 2019, wrestling commentator Jim Ross called Lynch “the most over talent in WWE”.

Lynch is a recurring guest on Xavier Woods’ YouTube channel UpUpDownDown, where she goes by the nickname ‘Soulless Senpai’. In October 2019, Lynch defeated Seth Rollins in a game of Marvel vs. Capcom: Infinite to win Rollins’ UpUpDownDown Championship. Lynch lost the title to Cesaro in Mario Kart 8 Deluxe a month later.

It was revealed that Quin was in a relationship with fellow wrestler Colby Lopez, known professionally as Seth Rollins. The couple announced their engagement on 22 August 2019. On 11 May 2020, Quin announced that she was expecting her first child in December and that their wedding, originally planned for May, would take place at a later time due to the COVID-19 pandemic.

Following Survivor Series, Lynch allied herself with Charlotte in a rivalry with Women’s Tag Team Champions The Kabuki Warriors (Asuka and Kairi Sane), leading to a Tables, Ladders and Chairs match for the championship between the two teams being arranged for TLC in December, which The Kabuki Warriors won. She then continued her feud with Asuka, which directed to a match for the Raw Women’s Championship at the Royal Rumble on 26 January 2020, where Lynch retained to end the feud.