Isaac Mabaya was born on 22 September 2004 in Preston, Lancashire, to Zimbabwean parents, and joined Liverpool's academy at the age of six. He developed through the club's youth system, initially as a midfielder before transitioning to right-back during the 2020–21 season. He signed his first professional contract with Liverpool in September 2021.
Mabaya caught attention during the 2021–22 season with strong performances for Liverpool's under-18 side, earning a place on the club's pre-season tour of the Far East in summer 2022, where he featured against Manchester United in Bangkok. His progress was interrupted by a season-ending ankle injury in October 2022, but he returned to sign a new contract in May 2023. He made his competitive first-team debut on 9 February 2025 in the FA Cup against Plymouth Argyle, coming on in the 11th minute after captain Joe Gomez was injured.
A composed, attack-minded right-back who is comfortable in one-on-one situations, Mabaya has shown he can step up when called upon at the highest level. He is currently on a season-long loan at EFL League One club Wigan Athletic for the 2025–26 season, where he is expected to build senior experience.
On the international front, Mabaya has represented England at under-18 and under-19 level, scoring on his England U18 debut against Sweden in March 2022. He received a senior call-up from Zimbabwe in November 2023 but did not feature in their final squad for World Cup qualifying matches.