Tennant has worked extensively on stage, including a portrayal of the title character in a 2008 Royal Shakespeare Company production of Hamlet that was later adapted for television.

Tennant's maternal grandfather, footballer Archie McLeod, met William and Agnes' daughter Nellie while playing for Derry City FC.

[12] His talent was noticed by actress Edith MacArthur, who told his parents that she believed he would become a successful theatre actor after she saw him perform when he was 10 years old.

[12] After discovering that there was another David McDonald already represented by the actor's union Equity, he created his stage name by adopting the surname of Pet Shop Boys frontman Neil Tennant, whom he had seen in Smash Hits.

Tennant's first professional role upon graduating from drama school was in a staging of The Resistible Rise of Arturo Ui co-starring Ashley Jensen, one of a few plays in which he performed as part of the agitprop 7:84 Theatre Company.

[12] He also made an early television appearance in the Scottish TV sitcom Rab C Nesbitt as a transgender barmaid called Davina.

His roles include a reprisal of his Antipholus of Syracuse in The Comedy of Errors, as well as Launcelot Gobbo in The Merchant of Venice, Edgar in King Lear, and Mercutio in Romeo and Juliet.

In 1995, Tennant appeared at the Royal National Theatre, London, playing the role of Nicholas Beckett in Joe Orton's What the Butler Saw.

[21] Tennant was nominated for Laurence Olivier Award for Best Actor in a Leading Role in a Play for his performance in Kenneth Lonergan's Lobby Hero.

Tennant replaced him as of the second series, making his first, brief appearance as the Tenth Doctor in the episode "The Parting of the Ways" (2005) at the end of the regeneration scene.

[31] In November 2017, three new audio dramas were released by Big Finish Productions, with Tennant once again starring as the Tenth Doctor, alongside Billie Piper as Rose Tyler.

He joined Franz Ferdinand onstage to play the guitar on their song "No You Girls" on a special Comic Relief edition of Top of the Pops.

[45] On 7 March 2010, Tennant appeared as George in a one-part BBC Radio 4 adaptation of Of Mice and Men in the Classic Serial strand.

[46] In October 2010 he starred as Dave, a man struggling to raise five children after the death of his partner, in the British drama Single Father.

[47] He joined the Royal Shakespeare Company (RSC), to play Hamlet with Patrick Stewart and Berowne in Love's Labours Lost in 2008.

[52] On 12 April 2011, a photograph of Tennant as Hamlet featured on a stamp issued by the Royal Mail to mark the RSC's fiftieth anniversary.

Later in September 2011, it was announced that Tennant would voice a character in the movie adaptation of Postman Pat with a planned 3D theatrical release for spring 2013.

[61] In January 2012, Tennant was appointed to the Royal Shakespeare Company board, to be on the selection committee interviewing and choosing the new artistic director.

[68] Tennant starred opposite Rosamund Pike and Billy Connolly in What We Did on Our Holiday, a semi-improvised comedy film; shooting took place from 17 June to 30 July 2013 in Scotland.

[76] Tennant played villain Cale Erendreich in the thriller film Bad Samaritan (2018), written by Brandon Boyce and directed by Dean Devlin.

[77] Tennant also plays Crowley in the series Good Omens,[78] the first season of which was released on Amazon Prime Video on 31 May 2019 and on BBC Two on 15 January 2020.

The podcast's episodes have featured Olivia Colman, Whoopi Goldberg, Jodie Whittaker, Ian McKellen, Jon Hamm, Gordon Brown, Jennifer Garner, Catherine Tate, Krysten Ritter, James Corden, Samantha Bee, Tina Fey, and Michael Sheen.

[81] Tennant starred as a doctor suspected of murdering his family in Deadwater Fell, a Scottish true crime miniseries, which premiered in January 2020 on Channel 4.

He played the lead part in Max Webster's production of Macbeth, which ran at the Donmar Warehouse in 2023 as well as the Harold Pinter Theatre in 2024.

In December 2008, he was named as one of the most influential people in show business by British theatre and entertainment magazine The Stage, making him the fifth actor to achieve a ranking in the top 20 (in a list typically dominated by producers and directors.

6 in its "Top Ten" list of the most influential British television artists of the year, citing his roles in Blackpool, Casanova, Secret Smile, and Doctor Who.

[109] Tennant remained neutral on the issue of Scottish independence in the run-up to the 2014 referendum, stating that it was not his business as he no longer lived in Scotland.

Prime Minister Rishi Sunak also criticised Tennant, saying that "if you're calling for women to shut up and wishing they didn't exist, you are the problem.

"[118] Labour leader and future prime minister Keir Starmer said that he "wouldn't have engaged the way [Tennant] did" and that discussions should be kept respectful.

[117] 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".