Coulson represented Leinster in underage rugby, before accepting an academy contract with French club FC Grenoble in 2014, who were then coached by ex-Leinster player and former St Michael's College head coach Bernard Jackman. He made 39 appearances for the club over three seasons.[2][3][4][5][6]
Connacht
In August 2017, Irish Pro14 side Connacht announced that they had signed Coulson ahead of the 2017–2018 season.[7] Coulson is an ex-Ireland U20 international.[8]