- Robbed a convenience store when he was 13 and got 6 months' probation.
- Expelled from school at age 15 for throwing a bag of flour on his teacher.
- Is a big soccer fan, and has always been a fan of of Manchester City F.C. and Celtic F.C.
- Was the main songwriter for his band Oasis which he quit in 2009 due to continuous arguments with bandmate and brother Liam Gallagher.
- Best friends with comedian Russell Brand, who was best man at his wedding in 2011.
- Peggy Gallagher — Mother
- Thomas Gallagher — Father
- Liam Gallagher — Brother
- Donovan Rory MacDonald Gallagher — Son
- Sonny Patrick MacDonald Gallagher — Son
- Meg Mathews — Ex-wife
- Paul Anthony Gallagher — Brother
- Anaïs Gallagher — Daughter
- Sara MacDonald — Wife