During his career, Pennington has played for several clubs, starting his youth career at Everton’s academy. He joined the Everton senior team in 2015 and went on to have loan spells at various clubs including Tranmere Rovers, Coventry City, Leeds United, Ipswich Town, and Shrewsbury Town. In 2020, he signed a permanent deal with Ipswich Town before moving to Blackpool FC in 2021.