Born in Plastow, Essex, John Keeley began his career at Southend United where he made 63 first team appearances between 1979 and 1986. He was signed by Brighton & Hove Albion in 1986 and made 138 league appearances in four years with the Seagulls, helping the club to promotion to the Second Division in 1988.
He joined Oldham Athletic in 1990, but made only two league appearances, being loaned out to Oxford United, Reading and Chester City in 1991 and 1992.
He joined Colchester United in 1993, making 15 league appearances. He subsequently joined Stockport County, making 20 league appearances. John later played for Peterborough United before retiring from the professional game.