Starting his career in France, Gomis spent most of his early career in English non-League football before moving to Scottish Football League side Cowdenbeath. His performances earned him a move to Dundee United in January 2007, where he exceeded expectations and was young player of the year for 2007–08. He was part of the Dundee United side that won the Scottish Cup in 2010 and was the first African to have played 100 times for the club. He left the club when his contract expired at the end of the 2010–11 season to join Football League Championship side Birmingham City. Gomis left Birmingham City in July 2013, having made 43 appearances for the club. He then rejoined Dundee United for a season before signing for Hearts in 2014. In 2016, he was loaned to Motherwell and made 10 appearances for the club before joining Kelantan in July 2016. After spending time with Omani club Sur SC in 2018, he returned to Scotland in January 2019 for a third spell with Dundee United, and joined Falkirk for the 2019–20 season. Following his release from Falkirk in May 2021 he signed for fellow Scottish League One club Clyde.