Shane Gallagher was born on December 30, 1973 in Fontana California. Shane is of South Korean descent. His mother Chong Suk Gallagher, was born and raised in Seoul, Korea before moving to the United States with her husband, Michael Gallagher. They had 2 children, Heather and Shane Gallagher.
In 2006, Gallagher left The Nervous Return to join Mark Hoppus and Travis Barker (both of blink-182 fame) and guitarist Craig Fairbaugh to form +44. He was brought in as a replacement for Carol Heller as guitarist in +44 after she left the band to start a family. In 2007, he officially became a member of The Mercy Killers and he went on tour with them. Once +44 took a break so Mark and Travis could focus on the new blink-182 record,Shane worked on several different musical projects including the Noise Chapter with ex-members of one of his previous bands called the Scrimmage Heroes as well as the present all instrumental, acoustic act A Death To Stars.