She played downtrodden Alice Harding in the ITV drama Where the Heart Is in 2004 and 2005[11] and has performed alongside her father Peter Davison in Fear, Stress & Anger[12] and The Last Detective.

[16][17] Tennant voiced the role of Cassie Rice in Doctor Who: Dreamland in 2009,[18] and portrayed Lady Vivian in the "Sweet Dreams" episode of the BBC drama Merlin.

[19] She joined the cast of BBC medical drama Casualty as junior doctor Heather Whitefield, her character was killed off at the start of her second episode.

In June 2010, she performed in the short play Hens, which ran for four performances at the Riverside Studios and was later broadcast on Sky Arts 2,[20] and played a cameo role in the television drama Thorne: Sleepyhead as the wife of one of the junior detectives (appearing in one scene in episode two, and one non-speaking scene in episode three).

In March 2011, she landed the role of Emma in the BBC Three sitcom White Van Man,[21] which ran for two series before being cancelled.

Tennant is a patron of Straight Talking, a charity set up to educate young people about teenage pregnancy.

[38] She is an outspoken ally to the LGBTQ community, having shared multiple posts in support on her Instagram as well as publicly wearing pins in the colours of trans- and non-binary flags.