Jamie Carson McDonnell (born 16 February 2004) is a Northern Irish professional footballer who plays, as a defensive midfielder for EFL Championship club Oxford United.
Born in Lisburn, McDonnell began his career with Lisburn Youth and Glentoran, before signing for Nottingham Forest in July 2020, where he turned professional in February 2021 after turning 17. After captaining their under-18 team, he agreed a new contract with Forest in December 2022.
McDonnell signed on loan for Colchester United in August 2024.
On 18 July 2025, McDonnell joined Mansfield Town on a season-long loan. He was one of three Nottingham Forest youth players to sign for Mansfield, alongside Joe Gardner and Kyle McAdam.
On 18 January 2026, McDonnell signed for Oxford United on a "long term contract" for an undisclosed fee. The move resulted in a six figure "windfall" for former club Glentoran.
McDonell is a Northern Ireland under-17 youth international.