Born in Colchester, Essex, Sowunmi is a graduate of the Ipswich Town academy, after impressing for the club's U18 and U21 sides he was rewarded with a one-year professional contract upon the completion of his academy scholarship in May 2014.[3] On 17 October 2014, Sowunmi joined Conference National side Braintree Town on a month's youth loan.[4] Sowunmi made four appearances in all competitions during his month on loan with the Essex side before returning to Ipswich in November.[5] He then joined Conference South side Lowestoft Town on loan in January 2015.[6] Sowunmi loan was eventually extended to the end of the 2014–15 season and he made a total of fifteen league appearances for Lowestoft,[7] and appeared twice and scored in the final of the Suffolk Premier Cup.[8]
Yeovil Town
With Lowestoft keen to sign Sowunmi permanently upon the expiry of his contract, the defender also had a trial with Exeter City, and was amongst a host of trialists to feature in an end of season trial match at Yeovil Town.[9] Having impressed manager Paul Sturrock, on 24 June 2015, Sowunmi signed a one-year contract with League Two side Yeovil Town.[10] Sowunmi made his debut for Yeovil as a substitute in Yeovil's 1–0 defeat against York City, on 18 August 2015.[11] He scored his first goal for Yeovil against Morecambe on 5 September 2015.[12]
He was offered a new contract by Yeovil at the end of the 2017–18 season.[13] He was captain during the 2018–19 season.[14]
Colchester United
On 1 July 2019, Sowunmi signed for his hometown club Colchester United for an undisclosed fee.[15] He made his club debut on 20 August, coming on as a substitute for Luke Norris in Colchester's 2–2 League Two draw at Grimsby Town.[16]
After 30 appearances for the club,[17] Sowunmi was released at the end of his contract in May 2021.[18]
Bromley
On 16 August 2021, Sowunmi signed for Bromley following a successful trial period with the club.[19]
Sutton United
On 16 June 2023, Sowunmi agreed to join League Two club Sutton United on a free transfer.[20]
Bromley
On 1 July 2024, Sowumni returned to newly promoted League Two side Bromley for an undisclosed fee.[21]
Personal life
Sowunmi was born in England to a Nigerian father and an English mother.[22]