O'Donohoe played for Belvedere College and Clontarf at an under-age level, and he also represented the Leinster Schools team 8 times.

O'Donohoe signed a professional contract with Leinster at the beginning of the 2008–09 season, joining the team's senior ranks.

O'Donohoe left Leinster at the end of the 2010–11 season, having made a total of 16 senior appearances for the side.

[4] O'Donohoe played his first European match for Connacht in the 2011–12 Heineken Cup, starting against English side Harlequins.

[7] At the start of the following season, both O'Donohoe and Murphy were absent due to injury,[8] meaning Connacht academy scrum-half Kieran Marmion stepped into the role.

He will depart the province at the end of the 2013–14 season, along with a number of other players, including Murphy, former Connacht captain Gavin Duffy and experienced fly-half Dan Parks.