Murphy's triumph was one of five awards picked up by the Christopher Nolan directed film, which also include Best Supporting Actor for Robert Downey Jr, Best Director for Nolan, Best Motion Picture - Drama, and Best Original Score - Motion Picture for Ludwig Goransson.
Peaky Blinders star Cillian Murphy was nominated in the Best Actor category, alongside Irish actors Andrew Scott (All Of Us Strangers), and Barry Keoghan (Saltburn), as well as Leonardo Di Caprio (Killers Of The Flower Moon), Bradley Cooper (Maestro), and Colman Domingo (Rustin).
In his speech after receiving the award, Cillian Murphy hailed the "visionary director" Nolan, "for having faith in me for 20 years and six feckin' pictures".
He also paid tribute to the movie's "incredible ensemble cast" for "carrying me and holding me through this movie".
"To all my fellow nominees, if you're Irish or not, you're all legends, stunning work - I salute you", Murphy added.
Finally, Cillian Murphy paid homage to his family, saying "I'm the luckiest man".
See the list of winners below.
Best Motion Picture – Drama
Oppenheimer
Best Performance by an Actress in a Motion Picture – Drama
Lily Gladstone – Killers of the Flower Moon
Best Picture – Musical or Comedy
Poor Things
Best Performance by an Actor in a Motion Picture – Musical or Comedy
Paul Giamatti – The Holdovers
Best Television Series – Drama
Succession
Best Performance by an Actress in a Television Series – Drama
Sarah Snook – Succession
Best Television Series – Musical or Comedy
The Bear
Best Limited Series, Anthology Series or a Motion Picture Made for Television
Beef
Cinematic and Box Office Achievement
Barbie
Best Original Song – Motion Picture
Barbie – What Was I Made For? by Billie Eilish and Finneas
Best Original Score – Motion Picture
Ludwig Göransson – Oppenheimer
Best Performance by an Actor in a Motion Picture – Drama
Cillian Murphy – Oppenheimer
Best Performance by an Actress in a Motion Picture – Musical or Comedy
Emma Stone – Poor Things
Best Director – Motion Picture
Christopher Nolan – Oppenheimer
Best Motion Picture – Animated
The Boy and the Heron
Best Performance by an Actor in a Television Series – Drama
Kieran Culkin – Succession
Best Actress in a TV Series – Musical or Comedy
Ayo Edebiri – The Bear
Best Picture – Non-English Language
Anatomy of a Fall – France
Best Performance in Stand-Up Comedy or Television
Ricky Gervais – Ricky Gervais: Armageddon
Best Actor in a TV Series – Musical or Comedy
Jeremy Allen White – The Bear
Best Screenplay – Motion Picture
Anatomy of a Fall – Justine Triet, Arthur Harari
Best Supporting Actor – Television
Matthew Macfadyen – Succession
Best Supporting Actress – Television
Elizabeth Debicki – The Crown
Best Performance by an Actor – Limited Series, Anthology Series or Motion Picture Made for Television
Steven Yeun – Beef
Best Performance by an Actress – Limited Series, Anthology Series or a Motion Picture Made for Television
Ali Wong – Beef
Best Supporting Actor – Motion Picture
Robert Downey Jr – Oppenheimer
Best Supporting Actress – Motion Picture
Da'Vine Joy Randolph – The Holdovers