The fourth series of the programme premiered on 4 January 2015 on RTÉ One and concluded on 26 April, similar to previous seasons.
Kathryn Thomas returned as main host, while her colleague Eoghan McDermott remained the show's co-host.
Television personalities Bressie and Kian Egan both returned as coaches, while The Saturdays singer Una Healy and S Club 7 star Rachel Stevens filled the remaining two positions.
After winning the recording contract with Universal, Donoghue decided to change his stage name to Patrick James as he found it represented him more as an artist.
This is where another coach saves a losing battle act from bowing out of the competition by drafting them to their Live Shows team.