Born: 25th February 1977
Episodes Broadcast: 2013-2015

As a teenager, London-born Ingrid Oliver started writing and performing comedy sketches in partnership with Lorna Watson, her classmate at Tiffin Girls' School, Kingston upon Thames. Oliver went on to study German and Italian at Oxford University, after which she trained as an actor. She considered pursuing a career in television production, but became disillusioned by the prospect. Instead, Oliver and Watson decided to resume their collaboration, and they were soon appearing annually at the Edinburgh Festival Fringe. In 2005, Oliver made her television debut in the telefilm Footprints In The Snow and an episode of Doc Martin. Shortly thereafter, she joined sketch shows like The Wrong Door as an actor and writer, while appearing regularly in the sitcom Plus One. A Watson & Oliver television special materialised in 2007. Oliver's movie debut came in the 2008 comedy Angus, Thongs And Perfect Snogging.

In 2010, Oliver could be heard in the Seventh Doctor audio drama Project: Destiny from Big Finish Productions. The popularity of her comedy double act led to a BBC Two series in 2012, with Watson & Oliver ultimately running for two seasons. Then, in 2013, Oliver joined the cast of Doctor Who as Petronella Osgood, a scientific adviser to the Unified Intelligence Taskforce who had the habit of adopting the various Doctors' fashion idiosyncracies. She debuted in the programme's fiftieth-anniversary special, The Day Of The Doctor, and went on to make two appearances opposite Peter Capaldi's Twelfth Doctor. Osgood was apparently killed by the Master in 2014's Dark Water / Death In Heaven, before the following year's The Zygon Invasion / The Zygon Inversion raised the possibility that the deceased Osgood may have been a Zygon duplicate.

Oliver's other television work during the 2010s included episodes of Material Girl, The Increasingly Poor Decisions Of Todd Margaret, Silent Witness and Defending The Guilty. On the silver screen, she could be seen in You, Me And Him starring former Doctor Who lead actor David Tennant, The Hustle with Anne Hathaway, and the Emilia Clarke holiday movie Last Christmas. Oliver also wrote and directed the short film The Story Of Ken. She began reprising Osgood for Big Finish, starting with the 2015 UNIT release Extinction. Amongst Oliver's work during the Twenties was a recurring role in The Watch. She was Osgood again for the 2022 podcast Doctor Who: Redacted from BBC Sounds.