Caleb studied writing at Flinders University under playwright Verity Laughton.

In 2002 he began a yearlong mentorship with Nick Enright and began work on Nailed.

In 2003 Lewis won the IAF Literature Scholarship to research the play Krissy Pho in Vietnam and also Naked Theatre Company’s Write Now competition for his play, RocketBaby.

In 2004 his play, Songs for the Deaf, was produced by FreshTrack Productions for the Adelaide Fringe Festival and he began a two-year residency with Griffin Theatre Company culminating in the world premiere of Nailed (short listed for the Phillip Parsons playwright's award) Caleb has completed commissions for Jigsaw Theatre Company (ACT) and Riverland Youth Theatre Company (SA) – His short film, The Half Windsor, opened in Sydney last May.

After receiving funding from the Australia Council Theatre Board and Literature Board, his play, The Sea Bride, won the Theatrelab Emerging Playwright Award earning a two-week workshop with playwright Edward Albee.

His new play Dogfall opens in Adelaide in November.

Caleb is currently writing, Otzi – the story of the Iceman, for the Australian National Maritime Museum.

In 2008, Songs for the Deaf tours to Hong Kong and his latest play, Men, Love and the Monkeyboy plays in Sydney.