 Gilmartin has played international football for the Republic of Ireland at under-19 and under-21 levels.Having previous played for St. Kevin's Boys, Gilmartin joined English League One side Walsall in the summer of 2005.He made his Walsall debut on 17 September 2005 in a 3–2 home defeat to Chesterfield, and played two further first-team matches that season.