[1] Raine was educated in Kington, Herefordshire, and wanted to be an actress from the age of 13, as her father starred in amateur dramatics with the Eardisley Little Theatre.

[5] After graduating in 2008, Raine began a successful stage career, initially cast as Lesley Sharp's goth daughter in Simon Stephens's Harper Regan.

[8] Raine played at the National Theatre in Mike Bartlett's Earthquakes in London as teenage wild-child Jasmine; and then as a secretary in the revival of Clifford Odets's Rocket to the Moon.

Later that year, she appeared as Doctor Who's original producer, Verity Lambert, in the fact-based drama An Adventure in Space and Time, showing the creation of the series as part of its 50th anniversary celebrations.

[13] In February 2014, Raine joined the cast of the BBC Two police drama Line of Duty for series two as Detective Constable Georgia Trotman, working for the AC12 anti-corruption unit.

"[14][15] In 2019, Raine played Genevieve Taylor, a British liaison officer for Europol in the Netherlands, in the BBC One drama series Baptiste.

[18] Raine began a relationship with fellow actor Tom Goodman-Hill after they met while appearing in the 2010 production of the play Earthquakes in London.