Marler was educated at Maynards Green Primary School and Heathfield Community College and began playing at the age of 11 for Eastbourne Sharks.[4] His stepping stones in the game not only include playing for Sussex Under 14-18 but also representing London & South East in 2006.
Marler joined the Harlequins Academy in 2008 and made his first team debut in the 2009-2010 season, after spending some time on loan to Esher and Worthing.[7] Marler has described his time in the lower tiers as a necessary learning curve that has allowed him to experience all the tricks of the trade at prop. He particularly points to the technical advice he received from one Bobby Walsh, a former coach, on scrummaging.[8] The knowledge gained at this level has allowed him to occasionally cover the tighthead side of the scrum.[9]
In May 2011 Marler started for the Harlequins side that defeated Stade Français in the final of the EPCR Challenge Cup.[10] The following season saw Marler play a crucial part in helping Harlequins claim their first ever League title by starting in the 2011–12 Premiership final victory over Leicester Tigers.[11]
Marler captained Harlequins for the 2014-2015 season, replacing Chris Robshaw due to his commitments as England captain in the 2015 World Cup year.[12] Marler then passed on the captaincy of Harlequins to teammate Danny Care in the following season.[13] In January 2016 it was announced that Marler had signed a new contract to stay at the club[14] and later that year he started for the Harlequins side that were defeated by Montpellier in the final of the EPCR Challenge Cup.[15]
On 26 June 2021 Marler won his second league title starting for the Harlequins side that defeated Exeter Chiefs 40-38 in the highest scoring Premiership final ever.[16]
New head coach Eddie Jones included Marler in his squad for the 2016 Six Nations Championship[31] and he came off the bench in the concluding game of the tournament as England defeated France to achieve their first grand slam in over a decade.[32] The following year saw Marler given the honour of leading the team out on his 50th cap against Scotland in the penultimate round of the 2017 Six Nations Championship.[33] He also started in the last round of the tournament defeat away to Ireland which ensured England failed to complete consecutive grand slams and also brought an end to a record equalling eighteen successive Test victories.[34]
In September 2018 Marler announced his retirement from international rugby[35] but later reversed his decision,[36] re-joining the England squad for the 2019 Rugby World Cup.[37] Marler came off the bench for the semi-final victory over New Zealand and was a second half replacement for Mako Vunipola in the final as England were defeated by South Africa to finish runners up.[38]
In March 2020, Marler was banned from playing for 10-weeks after he grabbed Alun Wyn Jones' genitals during a Six Nations match against Wales.[39] As a result of the coronavirus lockdown, the ban ended without Marler missing any matches since every fixture that Marler could have played was postponed.[40]
In September 2023, Marler returned to the England squad to play in the 2023 Rugby World Cup, his third World Cup with the senior side. In England's opening game vs Argentina, he replaced Ellis Genge in the 54th minute.[42] He played in all Group matches, the Quarter Final win against Fiji and the Semi Final loss to South Africa. He did not play in the Bronze Medal match against Argentina.
Marler attracted attention in October 2024 after tweeting that "the Haka needs binning", calling the All Blacks' pre-match ritual "ridiculous." His comments were widely criticised, including by New Zealand coach Scott Robertson, with academic Karaitiana Taiuru saying that Marler "lacked cultural appreciation."[43][44] Marler later apologised for his "poorly articulated" words, saying that he "meant no malice in asking for it to be binned, just want to see the restrictions lifted to allow for a response without sanction."[45]
He announced his retirement from the team on 3 November 2024.[46]
British & Irish Lions
On 19 April 2017, Marler was one of 41 players selected for the British & Irish Lions' tour to New Zealand in June and July of that year.[47] He made five appearances in the tour games but did not feature in the Test series against New Zealand.[48]
Barbarians
Marler was recruited into the Barbarians squad in 2019, making his only appearance for the team against England on 2 June alongside team mate James Horwill who captained the team. Marler returned to play for England again, 4 months later at the 2019 Rugby World Cup.[49]
Marler was recruited again to the squad in 2022, after missing out on a call up to England's 2022 Autumn nations series fixtures alongside fellow England international Zach Mercer. The squad was coached by Super Rugby champions' coach Scott Robertson and Heineken Cup winning coach Ronan O'Gara. The team faced the All Blacks XV on 13 November, with Marler also facing the Barbarians 5 days later with his club side Harlequins.[50]
Disciplinary issues
In April 2016 Marler received a two match ban and £20,000 fine (to be donated to a suitable equality charity) for using unsporting and discriminatory language towards Samson Lee during the England versus Wales Six Nations match held on 12 March.[51][52]
In December 2022, Marler received a 6 week ban (four of them suspended) for conduct prejudicial to the game involving insulting language used in an incident with Bristol Bears flanker Jake Heenan.[54][55]
Other ventures
In 2020, Marler wrote a book about his life: Loose Head, Confessions of an (un)professional rugby player, published by Ebury Press.[56]
He also hosts the podcast "Joe Marler's Things People Do" previously known as "The Joe Marler Show.".[57]
Marler has appeared as a celebrity panellist on BBC One gameshow The Wheel in November 2021[58] and the 2023 Christmas special.[59]