Born: 1976
Episodes Broadcast: 2014-2015, 2017

Yorkshire-born Peter Harness was a lifelong Doctor Who fan, numbering 1979's Destiny Of The Daleks amongst his earliest memories. In the mid-Nineties he attended Oxford University, where he completed a degree in English and served as president of the Oxford Revue. Harness' first play, Mongoose, was staged in 2003, initially at the Southwark Playhouse. The same year, he learned that Doctor Who would be returning to television under executive producer Russell T Davies. Harness contacted the BBC in the hope of writing for the show, but his brief resume curtailed his aspirations.

Instead, Harness honed his craft on other projects. His first television work came in 2005 on the MR James adaptation A View From A Hill. Subsequent scripts included City Of Vice, 1066 and Case Histories, plus the feature film Is Anybody There?. Having relocated to his wife's hometown of Malmö, Sweden, Harness became a regular contributor to the BBC's version of Wallander, which was set in the Swedish town of Ystad. Having now established his credentials, Harness was approached to write for Doctor Who's 2012-13 season. His first submission, “When We Weren't There”, was rejected, but a second idea about the Moon being an alien egg attracted more interest. Harness began developing it for Matt Smith's Eleventh Doctor, but he was then offered the opportunity to adapt Susanna Clarke's best-selling fantasy novel Jonathan Strange & Mr Norrell. Harness put his Doctor Who script on hold while he completed this assignment, for which he was also credited as an associate producer; in the meantime, he had also become an executive producer on Wallander.

By the time Harness returned to his Doctor Who adventure for the programme's 2014 season, he had to reimagine Kill The Moon to suit the Twelfth Doctor as played by Peter Capaldi. He went on to contribute stories to each of Capaldi's three seasons in the role, being co-credited on the latter two with executive producer Steven Moffat. Harness subsequently wrote McMafia and was an executive producer on his adaptation of HG Wells' The War Of The Worlds for the BBC. In 2023, Harness novelised his second Doctor Who script, 2015's The Zygon Invasion / The Zygon Inversion, for BBC Books.