The three-hour drama directed by Christopher Nolan outpaced gothic comedy Poor Things, another best picture contender that scored 11 nominations for the film industry's highest honours.
Both movies will compete with feminist doll adventure Barbie, Leonard Bernstein biopic Maestro, and Martin Scorsese's Killers of the Flower Moon, about the 1920s murders of members of the Osage Nation in Oklahoma, among others.
Nolan, a best director nominee, said it was "a real thrill" to see Oppenheimer pile up so many nominations.
"I think it's a great year for movies, and it's a real honour to be included," he said in an interview.
Greta Gerwig is not among the best director nominees despite Barbie taking the box office by storm. (AP PHOTO)
One of Hollywood's most acclaimed filmmakers, Nolan has never had a film win best picture at the Academy Awards.
Oppenheimer is considered the favourite for the top prize this year, based on early awards season wins and polling of experts by the Gold Derby website.
The remaining best picture nominees were American Fiction, The Holdovers, Past Lives, The Zone of Interest and French film Anatomy of a Fall.
Barbie, last year's highest-grossing movie, received eight nominations, including supporting actress for America Ferrera - who gave a memorable monologue about the challenges of womanhood - and supporting actor for Ryan Gosling.
Voters passed over Australian lead actress Margot Robbie and director Greta Gerwig.
Robert Downey Jr., Celine Song, Emma Stone and more react to their 2024 Oscar nominations. — The Academy (@TheAcademy) #Oscars https://t.co/BD2KaFAHxYJanuary 23, 2024
Oppenheimer secured a lead actor nomination for Cillian Murphy, who played scientist J Robert Oppenheimer, and for supporting cast Emily Blunt and Robert Downey Jr.
With Barbie and Oppenheimer in the mix, the Oscars telecast on March 10 will showcase two big-screen blockbusters.
The films collected nearly $US2.4 billion ($A3.6 billion) combined in a summer box office battle dubbed Barbenheimer.
Ten of the 20 acting contenders were first-time nominees.
Among them were Native American Killers of the Flower Moon star Lily Gladstone, and Jeffrey Wright and Sterling K Brown for American Fiction, the story of a Black writer fed up with book publishers pushing stereotypes.
Director Christopher Nolan said it was "a real thrill" to see Oppenheimer get so many nominations. (AP PHOTO)
Wright said he did not watch the nominations announcement, which were presented by actors Jack Quaid and Zazie Beetz.
"I did not want to have to break a screen," he joked. "So, I just let it all happen."
Colman Domingo, nominated for playing gay civil rights leader Bayard Rustin in Rustin, did tune in.
"I listened, watched my husband listen to my name being called, and then I watched him lay down on the floor and start crying," Domingo said.
"And then, of course, I picked him up and we both had a little cry together."
Actors Jack Quaid and Zazie Beetz announced the Oscar nominees in Beverly Hills. (AP PHOTO)
In a surprise, voters snubbed Flower Moon actor and past Oscar winner Leonardo DiCaprio.
Fellow Oscar winner Robert De Niro received a supporting actor nomination for the movie.
Emma Stone nabbed a best actress nod for her role in Poor Things as Bella, a woman who goes on a journey of self-discovery after being raised from the dead.
"I am forever thankful for the opportunity to play Bella and see the world through her eyes," said Stone, another previous Oscar winner, who was also nominated for best picture as a Poor Things producer.
Winners of the gold Oscar statuettes will be chosen by the roughly 11,000 actors, producers, directors and film craftspeople who make up the Academy of Motion Picture Arts and Sciences.
Late-night talk show's Jimmy Kimmel will for the fourth time host the Oscars ceremony.
For best original song, Gosling's lament I'm Just Ken will compete with Billie Eilish's What Was I Made For?, also from Barbie.
