Born in Luton, Bedfordshire, Keane made his first-team debut for Luton Town under manager Mike Newell at the age of 16, in a Football League Trophy victory against Rushden & Diamonds early in the 2003–04 season. Keane played well and stayed in the side for a further 16 games that season, his league debut coming in a 0–0 draw at Wycombe Wanderers in February 2004. Newell predominantly played Keane at right-back as cover for Kevin Foley, but he also featured in midfield. Keane scored his first goal for Luton on 17 April as a last minute winner in a 3–2 victory over Bristol City.