Catherine Tregenna is a Welsh playwright, television scriptwriter and actress.
She wrote the play Art and Guff, co-wrote the series Cowbois ac Injans and four episodes of the BBC's science fiction drama Torchwood: "Out of Time", "Captain Jack Harkness", "Meat" and "Adam". "Captain Jack Harkness" was nominated for the 2008 Hugo Award for Best Dramatic Presentation, Short Form.
She has also written episodes for EastEnders, Casualty and for the first four series of ITV1 crime drama Law & Order: UK, which began transmitting in February 2009.
She played the character Kirsty McGurk, for several years, in Pobol Y Cwm and a doctor in Satellite City.