And Ellie Bamber will play Keeler's friend Mandy Rice-Davies.
Keeler was later charged with perjury and sentenced to nine months prison, where she served four and a half months before being released in 1964.
The pair hit the headlines after seven shots were fired at Ward's house in a quiet Marylebone mews by a jilted boyfriend of Keeler a year later in December 1962.
Sophie Cookson is a critically acclaimed English actress.
She gained mainstream exposure for her starring roles in the Kingsman franchise, The Huntsman: Winter's War, and The Trial of Christine Keeler.
As the story, which happened at the height of the Cold War, unravelled it was revealed Keeler, who denied being a prostitute, had also slept with another powerful man at the same time as her affair with Profumo — Soviet naval attache, Yevgeny Ivanov.
When Keeler died in 2017, obituary writers were quick to describe her as being a showgirl who was prone to making wild claims about her part in the affair.
The situation became rather tense and reached an impasse.