David John Tennant is a Scottish actor. He is best known for portraying the tenth incarnation of the Doctor in the sci-fi series Doctor Who (2005–2010; 2013). He returned to the show as the fourteenth incarnation of the character from 2022 to 2023. His other notable screen roles include DI Alec Hardy in the crime drama series Broadchurch (2013–2017) and its 2014 remake, Kilgrave in the superhero series Jessica Jones (2015–2019), Crowley in the fantasy series Good Omens (2019–present) and various fictionalised versions of himself in the comedy series Staged (2020–2022).

Tennant was born David John McDonald in Bathgate on 18 April 1971, the son of Helen (née McLeod; 1940–2007) and Alexander "Sandy" McDonald (1937–2016). His father was a minister who served as the Moderator of the General Assembly of the Church of Scotland. He grew up with his brother Blair and sister Karen in Ralston, where his father was the local minister. Two of his maternal great-grandparents, William and Agnes Blair, were Northern Irish Protestants from County Londonderry who were among the signatories of the Ulster Covenant in 1912; William was also a member of the Orange Order. Tennant's maternal grandfather, footballer Archie McLeod, met William and Agnes' daughter Nellie while playing for Derry City FC. McLeod was descended from tenant farmers from the Isle of Mull. Tennant has suffered from anxiety since childhood.

Tennant has rarely discussed his private life in interviews, citing his belief that "relationships are hard enough with the people you're having them with, let alone talking about them in public". Tennant, whose father was a Church of Scotland minister, believes religion "must have" shaped his character, and revealed that he is an occasional churchgoer.