Born in Stockport, Greater Manchester, Keane and his twin brother Michael grew up in the suburb of Heaton Mersey and attended St Bede's College in south Manchester. They were spotted playing football for South Manchester by Manchester United at the age of 11, and soon joined the club's academy coaching system.

Having declared for Ireland in February 2019, Stephen Kenny brought the Wigan striker into the squad for the Azerbaijan and Qatar fixtures in September after his impressive form in the 2021 season.

Keane came back into the squad for the November fixtures and he made his debut for Ireland in the final stages of the 0-0 draw against Portugal at the Aviva Stadium.