The Secret Diaries of a Call Girl star will play Jenny, one half of a feuding couple who have split up, but refuse to leave their shared house.
Penned by Star Stories and Kevin Bishop Show writer Lee Hupfield and directed by The Inbetweeners Movie helmer Ben Palmer, the Objective Productions pilot was one of a raft of new shows announced by BBC Three controller Zai Bennett over the weekend.
"It's been a busy five months since I started with the channel but my thoughts for BBC Three are starting to take shape," said Bennett.
"These programmes reaffirm my commitment to continue investing in new British comedy and quality documentaries for a young audience."
Tom and Jenny joins a new-look lineup of comedies on BBC Three including a second series of Will Mellor's White Van Man and Sharon Horgan's highly-anticipated new series Life Story.
Other news shows confirmed by Bennett included documetaries Gareth Gates Stammer House, a Born Survivors season and comedian Andrew Maxwell's 9/11 - Conspiracy Road Trip.