[1] As a child, he was initially against the idea of being a musician; however, he ended up dropping out of school to pursue a musical career.

After its moderate success, O'Donoghue moved to Los Angeles with Sheehan to write songs and produce for artists such as Britney Spears, Boyz II Men and TLC.

[4] After one year of writing, O'Donoghue and Sheehan moved back to Dublin and, recruiting drummer Glen Power, started working on their own material.

In 2012 O'Donoghue made his first appearance in The Voice UK alongside Jessie J, will.i.am and Tom Jones as a coach.

The decision was supported by bandmates Glen Power and Mark Sheehan, who said: "Danny did The Voice to put a face to The Script.

"[8] The appointment of O'Donoghue as coach initially drew criticism, with Twitter users branding him "Danny I Dunno Who" and comedian James Corden joking about it at the 2012 BRIT Awards.

The rose tattoo on O'Donoghue's left arm[12] and the song "If You Could See Me Now" from their album #3 are dedicated to the memory of his father.

[13][14] In June 2024, O'Donoghue revealed he attends Catholic Mass daily and gave up on alcohol, smoking and caffeine.