The Crown star, who is known for her cropped brunette locks, showed off her stunning new hairstyle on the red carpet, alongside her husband Ed Sinclair.
Olivia looked almost unrecognisable at the UK film premiere, which was held in London tonight, turning heads in a chic black gown.
The actress opted for a racy twist on the classic look, with her dress featuring a plunging sheer cut-out neckline.
Olivia stars as Mrs. Scrubbit in the upcoming fantasy film, which chronicles the origin story of Roald Dahl’s iconic Charlie and the Chocolate Factory character, Willy Wonka, who is being portrayed by Timothee Chalamet.
The prequel is set for release on December 8, when cinema-goers will also be treated to performances from Hugh Grant as an Oompa Loompa, alongside fellow British acting talent, including Sally Hawkins and Rowan Atkinson.