Cooke was born on December 27, 1993, in Oldham - part of the Greater Manchester area. She attended Royton and Crompton Academy and studied drama at Oldham Sixth Form College, leaving before the end of her A-levels to appear in Blackout (2012).
Cooke is best known for co-starring in Ready Player One (2018). She also appeared as a series regular on Bates Motel for its entire run (2013-2017), and in the film Thoroughbreds (2017). Later Cooke played the lead role in the 2018 miniseries adaptation of Vanity Fair.
Olivia Cooke is two years younger than Emma D'Arcy, who plays Alicent's step-daughter Rhaenyra Targaryen. In the books, Alicent is nine years older than Rhaenyra - still a small age gap, because Alicent isn't her biological mother. The books state that even in her 40's, Alicent continued to look notably young for her age, while Rhaenyra was haggard from several difficult pregnancies that left her looking older than her years. The result was that the visible age difference between Alicent and Rhaenyra seemed even smaller.
On a day to day basis, most people who know Olivia call her "Liv".