Born in Dorset. He trained at the Drama Centre London and made his acting debut in 2008 on Wallander alongside Kenneth Branagh. Between 2011 and 2012 he had a recurring role in the TV series Monroe as Daniel Springer. Allen-Gale also had a recurring role as william Whele in the series Dominion between 2014 and 2015.
Allen-Gale has had roles in a number of Short films between 2009 and 2011. In 2010 he provided the voice of Spiller in the UK adaptation of the animated film The Secret World of Arrietty. In 2016, Allen-Gale took had a lead role as Inspector Godfrey in The CW TV Movie Transylvania.
He made his professional West End stage debut in 2014 as Nicky Lockridge in Richard Greenberg's The American Plan, which transferred to the St James Theatre in London from Theatre Royal, Bath.
