Dunn initially played rugby at
Chippenham RFC. He joined Bath Rugby’s senior setup in 2012, making his professional debut against
Calvisano in the
European Challenge Cup. Early in his professional career, he spent short loan spells with
London Scottish and
Rotherham Titans. Dunn started in the
2013–14 European Challenge Cup final which Bath lost against
Northampton Saints at
Cardiff Arms Park to finish runners-up. Dunn was Bath’s top try-scorer in the Premiership in the
2022–23 season, recording a dozen tries, including a memorable hat-trick against
Saracens in the final game of the season. In 2023, Dunn celebrated a milestone by reaching 200 appearances for Bath Rugby, becoming one of 10 players to achieve the career landmark in the professional era, joining the likes of
Nick Abendanon,
Olly Barkley,
David Flatman and
Matt Banahan. At the end of that campaign he started in the Premiership final which they lost against Northampton. Dunn scored two tries in the
2024–25 Premiership Rugby Cup final as Bath beat
Exeter Chiefs to win their first domestic trophy since 1996. He also scored a try during the
2024–25 EPCR Challenge Cup final which saw Bath defeat
Lyon at the
Millennium Stadium to win their first European trophy for seventeen years. In May 2025, Dunn set a new club record for the most Premiership appearances for Bath, surpassing
David Barnes, playing in his 184th Premiership match. Dunn scored a memorable try in the 47th minute of this match, following an elaborate dummy and a subsequent 20-metre sprint to the line. At the end of that campaign he started in the
2024–25 Premiership Rugby final which saw Bath defeat
Leicester Tigers to become champions of England for the first time since 1996. ==International career==