Ayr Russell initially played rugby at
Stirling County, but in 2011 moved to second-flight
Falkirk to improve his chances of first XV club rugby. Russell was selected to play for
Ayr after the IRB Championship tournament, helping them win the league and cup double in the 2012–13 season of the
Scottish Premiership. Russell joined
Glasgow Warriors in 2012, but was injured in his first season.
Glasgow Warriors Russell returned to Glasgow for the 2013/14 season. With Glasgow's top players away on international duty for the
2013 Six Nations Championship, Russell was named on the bench to face
Zebre on 10 February 2013 as part of the
2012–13 Pro12 season, coming onto the field and making his professional debut at the 56th minute of the game. During the
2013–14 Pro12 season, Russell made his first start at the club, starting at Inside Centre against the
Newport Gwent Dragons at
Scotstoun Stadium on 22 November 2013. Glasgow head coach Gregor Townsend offered Russell a full-time contract with the club that began in the 2014–15 season.
2014–15 also saw Russell play a prominent role in Glasgow's Pro12 title triumph. In the final match of the regular season, he scored 22 points (including two tries) in a bonus-point victory over
Ulster which was needed to secure a home play-off. The following week, against the same opposition, Russell's pass to
D. T. H. van der Merwe in the 75th minute resulted in a try, tying the score at 14–14. Russell then scored the decisive conversion from a wide angle to send Glasgow into the final. In the
final at
Belfast's
Ravenhill Stadium, Russell scored a try and four conversions in a 31–13 victory over Munster, as Glasgow won their maiden title.
Racing 92 On 29 November 2017, it was announced that Russell would leave Glasgow Warriors at the end of the
2017–18 season to play for French club
Racing 92, where he was to replace
All Black Dan Carter who was moving to Japan. In December 2022, it was announced that Russell would join
Bath Rugby after the
2023 Rugby World Cup.
Bath Following Scotland's early exit from the 2023 Rugby World Cup, Russell made his Bath debut as a substitute in the opening round of the
2023-24 Premiership Rugby season, contributing to Bath's 34-26 victory over
Newcastle Falcons. Russell sustained a groin injury during Bath's
Investec Champions Cup defeat to
Exeter Chiefs, taking him out of action for five weeks. He returned for the final two rounds of the regular season, playing a crucial role in helping Bath reach the playoffs for the first time in four years. In the semi-final against
Sale Sharks, Russell scored 16 points, leading Bath to a 31-23 victory and securing their first Premiership Final appearance in nine years. However, Bath fell to
Northampton Saints, losing the final 25-21. He was instrumental in Bath's run to the final of the
2024–25 EPCR Challenge Cup, where they lifted the trophy after beating
Lyon 37–12. Russell won his second career league title in June 2025, scoring 13 points and setting up a try as Bath defeated
Leicester Tigers in the
2024–25 Premiership Rugby Final. On the 19th of June 2025, just five days after winning the
2024-25 Premiership Rugby Final,
Bath Rugby announced Russell had signed a contract extension up until June 2028, adding another two years to his contract that had been due to run out in Summer 2026. == International career ==