Cillian Murphy has won the Oscar for best actor for his role in Oppenheimer at the 96th Academy Awards.

Murphy has the title role in the film, a biopic of pioneering atomic-weapons scientist J Robert Oppenheimer written and directed by Christopher Nolan, and based on American Prometheus by Kai Bird and Martin J Sherwin. It marked Murphy’s sixth collaboration with Nolan, having first appeared as the Scarecrow in Nolan’s Batman Begins.

Murphy defeated a strong field for the Oscar, including Paul Giamatti for The Holdovers, Jeffrey Wright for American Fiction and Bradley Cooper for Maestro. This was Murphy’s first Oscar nomination, but he was considered the favourite after winning a string of previous awards for the film, including best actor at the Baftas and Screen Actors Guild, and best actor (drama) at the Golden Globes. Previously, he was the lead in the Ken Loach-directed The Wind That Shakes the Barley, winner of the Palme d’Or in Cannes in 2006, as well as winning two National Television Awards for period gangster series Peaky Blinders.

Murphy is the third Irish actor to win the best actor Oscar, following Daniel Day-Lewis, who was born in London but holds Irish citizenship, and Barry Fitzgerald who won in 1945.

Murphy thanked Nolan and Emma Thomas, his producer, as well as his team and his family. He ended his speech by saying he was a “very very proud Irishman”.

“We made a film about the man who created the atomic bomb and for better or worse we’re now living in Oppenheimer’s world now. So I’d like to dedicate this to the peacemakers everywhere.”

Read more about the 2024 Oscars:

• Here’s our news wrap and full list of winners – now read Peter Bradshaw’s verdict
• Al Pacino, British mothers and a codpiece envelope: the real winners and losers of the night
• Relive how the ceremony unfolded with our liveblog and get up to speed with the top viral moments and the best quotes of the night
• Have a gander at how the stars looked on the red carpet and at the show