Leighton Allen played for Norwich's youth-team on 6th December 1989, coming on as substitute whilst on trial with the club. He was a forward.

By 1992/93 he was with Wimbledon but was released in the summer of 1994 without playing for their first team. After a trial that summer with Gillingham, he joined Colchester on 1st August 1994 and made two league appearances before being released the following month.

By January 1996 he was with non-league Ringmer. He later played for Crawley Town, Saltdean United, Lewes, Peacehaven & Telscombe, Wealden, Ringmer and Wealden again, leaving in the summer of 2004.