Sai Bennett

Bennett was born in Aldershot, Hampshire and grew up in Hackney, East London with her older sister and younger brother. She is of Welsh descent. She attended the now defunct Royal School, Hampstead and left at sixteen after completing her GCSEs. She traveled and worked odd jobs before her former school drama teacher suggested she try acting. She began taking weekend acting classes and signed with an agent. Her brother also took part in local theatre. Bennett was 13 when she booked her first modeling job for Japanese Vogue. She signed with Storm Models. She featured in Cosmopolitan's 2011 Sexy Eyes photoshoot. She also had gigs with Urban Outfitters, Hollister Co., and Daisy London.

In 2012, Bennett made both her film and television debuts in Trapped as Emily and the first series of the BBC One drama Prisoners' Wives as Saskia. In 2014, she joined the cast of ITV period drama Mr Selfridge for its second and third series as the seamstress Jessie Pertree and played Elizabeth Pryce in Michael Winterbottom's psychological thriller The Face of an Angel. This was followed by roles in the 2015 film Just Jim and the 2016 BBC Two 1940s-set miniseries Close to the Enemy.

Bennett starred in the 2018 Syfy television film sequels Lake Placid: Legacy directed by Darrell Roodt and Leprechaun Returns. She appeared in Greta Bellamacina's Hurt by Paradise in 2019. That same year, it was announced Bennett would star as Mary Tudor, later Queen of France, in the latter half of the Starz historical miniseries The Spanish Princess, which aired in 2020. She appeared in the 2022 BBC Three musical drama Mood.