Has an older half brother, Lennon Gallagher, and an older half sister, Molly Moorish, from his father's side. Has a younger sister, Skipper, from her mother's side.
On June 2019 Gene was expelled from King Alfred School in Golder's Green, where pupils are charged £6,459 a term.
He is English of Irish descent from his father's side (his paternal grandparents were Irish), and of Canadian-Jewish descent from his mother's side.