Jo Martin (born 29 April) played Ruth Clayton/Fugitive Doctor in the Doctor Who television stories Fugitive of the Judoon, The Timeless Children and Once, Upon Time. alongside Jodie Whittaker's Thirteenth Doctor. She was the second non-white actor to be cast in the role of the Doctor in the DWU and the first to be explicitly portrayed as the Doctor; Steven Moffat stated in a 2008 email exchange with Russell T Davies that Doctor Moon, played by Anglo-Jamaican actor Colin Salmon, was similarly intended to be a future incarnation of the Doctor, but this goes unstated in Silence in the Library/Forest of the Dead. (REF: Showrunner Showdown)
In an interview with DWM 549, Martin mentioned that she had watched the show as a child, and had always wanted a part in it.
At the time of her Doctor Who appearance, Martin was perhaps better known as Max McGerry in the hospital drama series Holby City (1999–2022).