Famous as the lead singer of the Irish indie rock band Kodaline, Garrigan founded the group in 2005 with his childhood friend Mark Prendergast. In 2013, Kodaline released a debut studio album titled In a Perfect World.
In late 2006, Kodaline, which was then called 21 Demands, finished second in a popular Irish RTE network talent competition.
"Honest," a track from the 2015 Kodaline album Coming Up For Air, rose to number eleven on Irish music charts.
He began dating author Diana Bunici. Garrigan and his bandmates Mark Prendergast and Vinny May grew up in the Dublin suburb of Swords, Ireland. Bassist Jason Boland, who joined the group several years after its founding, was raised in Celbridge, County Kildare.
His song "Pray" was featured in a 2013 Alexandre Aja fantasy film titled Horns.