Allen's film work includes Colour Me Kubrick with John Malkovich, Starter for Ten with James McAvoy and Mark Gatiss, and Tamara Drewe.
In October 2016, he appeared as a guest on BBC2's The Great British Bake Off: An Extra Slice, and in January 2017, he made his debut on Live at the Apollo in an episode hosted by Sarah Millican.
In July 2017, he appeared on a celebrity special version of gameshow The Crystal Maze[8] and – an hour later the same night – on Mock the Week.
Allen competed on Richard Osman's House of Games in 2020,[12] alongside Chizzy Akudolu, Charlie Higson, and Kate Williams.
In December 2020, Allen co hosted The Great Christmas Bake Off alongside Matt Lucas as a replacement for Noel Fielding due to his paternity leave following the birth of his second child.
He took the lead role of young Pip Bin in the BBC Radio 4 comedy Bleak Expectations, which has so far run to five series (2007, 2008, 2009, 2010 and 2012), co-starring with Anthony Stewart Head and Richard Johnson.
[27] In 2008, he recorded a radio adaptation of The Wooden Overcoat with Julia Davis and David Tennant, written by Mark Gatiss.
[29] In 2018, as part of a series of comedy stand-up specials on BBC Radio 4, a programme titled Tom Allen Is Actually Not Very Nice was broadcast on 22 April.
His character is a city trader from 1966, who joined the First Doctor and Taylor in the audio plays The Perpetual Bond, The Cold Equations and The First Wave.
[25][36] He has spoken of his difficulties growing up as "closeted, working-class kid in Bromley" and homophobic bullying at school,[36] saying "'Why do you talk about being gay all the time?'
They have discussed their time at Coopers School and their friendship during appearances on 8 Out of 10 Cats, The Great British Bake Off, Sunday Brunch, and elsewhere.