In 2002, he made his debut as a professional comedian by taking on the role of Viola in The Night of the Kings at Middle Temple Hall. In 2004, he won the 50th Evening Standard Theater Award for best revelation for his role in Edward Albee's The Goat, or Who Is Sylvia ?, and the Critics' Circle Theater Awards a year later . Then, he plays in Christopher Shinn's Now or Later at the Royal Court Theater.

In 2009, Eddie Redmayne appeared in John Logan's new play, Red, at Donmar Warehouse in London, for which he won the Laurence Olivier Award for Best Supporting Actress in 2010. He took up his role at the John Golden Theater on Broadway in 2010 and receives the Best Actor Award at the 64th Tony Awards.

Her main television roles include Angel Clare in the BBC miniseries, Tess of the D'Urbervilles, Jack Jackson, Ken Television's eponymous adaptation of Ken Follett's eponymous novel, The Pillars of the Earth, as well as that of Stephen Wraysford in the Birdsong mini-series, taken from Sebastian Faulks's novel.

In the movies, he played supporting roles in Reasons of State, Powder Blue, Savage Grace, Two Sisters for a King and 1939. He toured with Kristen Stewart in 2008 in the independent film The Yellow Handkerchief, where he played the role of Gordy , a strange young man. The film is released in the United States two years later but remains unpublished in France. Then in 2010, he obtains the lead role of Christopher Smith's Black Death horror film, where he plays the role of Osmund, a monk confronted by an epidemic of bubonic plague and a mysterious necromancer.

Returning to the theater, he took on the role of King Richard II of England in Richard II's Shakespearian play directed by Michael Grandage at Donmar Warehouse from December 6, 2011 to February 4, 2012.

He shares the movie poster My Week with Marilyn with Michelle Williams where he plays the role of Colin Clark, young assistant director,1. In 2012, he took over the role of Marius Pontmercy in the film adaptation of the musical Les Misérables, which was inspired by Victor Hugo's novel. In 2015, he appeared on James Marsch's film A Wonderful Story of Time, where he played the role of physicist and cosmologist Stephen Hawking, which earned him the Oscar for Best Actor.

On June 2, 2015, after two months of rumors, Warner Bros. officially announces that he will play the role of Norbert Dragonneau, the main character of the Fantastic Animals. The film, released in November 2016, is the first episode of a pentalogy adapted from the wizarding world of J. K. Rowling. The second film, The Crimes of Grindelwald, was released in 2018.