Tommy O'Sullivan

Colchester United After failing to make an impact on the Cardiff first-team during the 2016–17 season, O'Sullivan joined Colchester United on trial in January 2017, completing a transfer to the club for an undisclosed fee on 20 January 2017. He made his debut as a substitute for Drey Wright after 78-minutes of Colchester's 4–0 League Two win at home to Stevenage on 8 April. He made three first-team appearances in 2016–17.

On 4 January 2018, O'Sullivan signed for National League side Torquay United on loan until the end of the season. He made his debut two days later in a 4–0 defeat at Wrexham. He played a total of seven games for Gary Owers's "Gulls", who ended the season being relegated into the National League South. Upon his return to the Colchester Community Stadium at the end of the 2017–18 season he was released by manager John McGreal.

Hereford On 25 October 2018, O'Sullivan signed with National League North side Hereford after a successful trial period at Edgar Street. He featured 31 times for the "Bulls" throughout the 2018–19 season. He was reunited with former Cardiff manager Russell Slade in September 2019 following Marc Richards' departure from the club. O'Sullivan's 96th-minute winner against Gateshead on 17 September secured Slade's first victory at Edgar Street. He scored two goals in 22 appearances in the 2019–20 season, which was permanently suspended on 26 March due to the COVID-19 pandemic in England, with Hereford in 15th-place.

Gloucester City On 7 August 2020, O'Sullivan joined Hereford's National League North rivals Gloucester City, becoming manager James Rowe's fifth summer signing. He made 21 appearances before the 2020–21 season was curtailed due to the ongoing pandemic. He featured 36 times under Lee Mansell in the 2021–22 season, in what O'Sullivan called "a transitional time" at Meadow Park. He played 38 league games in the 2023–24 season to help Brackley to secure a play-off place with a third-place finish. He scored two goals in 37 matches throughout the 2024–25 season as Brackley secured promotion as champions of the National League North; manager Gavin Cowan said the team had accomplished "something extraordinary" in reaching the National League for the first time in the club's history. He left the club at the end of his contract as he felt "that he needs guarantees at this stage of his career and that he needs every minute on the pitch".

Samui United On 21 August 2025, O'Sullivan signed with Thai League 3 club Samui United. He coached at The International School of Samui in October 2025.

International career O'Sullivan has represented Wales at under-17, under-19 and under-21 level. He made his competitive debut for the under-17s starting in a 3–2 defeat to Armenia on 17 October 2011. He made five appearances for the under-17 side. He scored six goals in six appearances for the under-19 team. For his first goals at under-21 level, he scored a brace against Bulgaria during a 3–1 win on 31 March 2015. He scored three goals in 15 competitive under-21 games between 2013 and 2016.

Coaching career In 2022, he was coaching in the academy at Cardiff City.

Personal life Tommy's elder brother, Sam O'Sullivan, played 152 times for Newport County before leaving the club in 2008.

Career statistics

Honours Brackley Town: National League North: 2024–25

Individual Football Association of Wales Young Player of the Year: 2014–15