Dalton's best friend, stunt double, personal assistant and driver is Cliff Booth—a World War II veteran living in a trailer with his pit bull Brandy.

The man, Charles Manson, claims to be looking for music producer Terry Melcher, who once lived there, but Tate's friend Jay Sebring turns him away.

[9] Additionally, the film features appearances from Clifton Collins Jr. as Ernesto "The Mexican" Vaquero, a character on Lancer, Omar Doom as Donnie, a biker on Spahn Ranch, Clu Gulager (in his last film role) as a book store owner, Perla Haney-Jardine as an LSD-selling hippie, Martin Kove and James Remar as a Sheriff and "Ugly Owl Hoot", two characters on Bounty Law, Brenda Vaccaro as Schwarz's wife Mary Alice, Tarantino's wife Daniella Pick as Daphna Ben-Cobo, Dalton's co-star in Nebraska Jim, Lew Temple, Vincent Laresca, JLouis Mills and Maurice Compte as Land Pirates, and Gabriela Flores as Maralu the Fiddle Player.

While he knew he wanted it to be titled Once Upon a Time in Hollywood, evoking the idea of a fairy tale, he publicly referred to the project as Magnum opus.

[103] Tarantino's demands included a $95 million budget, final cut privilege, "extraordinary creative controls", 25% of first-dollar gross, and the stipulation that the rights revert to him after 10 to 20 years.

[114] In June 2018, Damian Lewis, Luke Perry, Emile Hirsch, Dakota Fanning, Clifton Collins Jr., Keith Jefferson, Nicholas Hammond, Pacino, and Scoot McNairy joined the cast.

[118] In August 2018, Damon Herriman as Charles Manson, and Lena Dunham, Austin Butler, Danny Strong, Rafał Zawierucha, Rumer Willis, Dreama Walker, and Margaret Qualley were cast.

And even that shot, that kind of looks up at Cliff as he drives by the Earl Scheib, and all those signs, that's pretty much my perspective, being a little kid...[26]Principal photography began on June 18, 2018, in Los Angeles, California, and wrapped on November 1, 2018.

[135] He and Renato Casaro created the posters for the movies within the film, Nebraska Jim, Operation Dyn-O-Mite, Uccidimi Subito Ringo Disse il Gringo, Hell-Fire Texas, and Comanche Uprising, which was reprinted for Dalton's home parking spot.

Afterwards Tarantino came up with the idea for Dalton's "freakout" scene in his trailer, taking inspiration from Robert De Niro's performance in Martin Scorsese's Taxi Driver.

[144] The soundtrack from the film is a compilation album of classic rock, which includes multiple tracks from Paul Revere & the Raiders, as well as 1960s radio ads and DJ patter.

[148] The official trailer was released on May 21, 2019, featuring the songs "Good Thing" by Paul Revere & the Raiders, and "Brother Love's Travelling Salvation Show" by Neil Diamond.

[153] Both the DVD and Blu-ray contain a deleted scene, in which Charles Manson confronts Paul Barabuta, portrayed by Danny Strong, the homeowner and caretaker of the Tate-Polanski residence.

The website's consensus reads: "Thrillingly unrestrained yet solidly crafted, Once Upon a Time in Hollywood tempers Tarantino's provocative impulses with the clarity of a mature filmmaker's vision.

[169] The Chicago Sun-Times, Richard Roeper described it as "a brilliant and sometimes outrageously fantastic mash-up of real-life events and characters with pure fiction", giving it full marks.

[170] Peter Bradshaw of The Guardian gave it five out of five stars, praising Pitt and DiCaprio's performances and calling it "Tarantino's dazzling LA redemption song".

[171] Steve Pond of TheWrap said: "Big, brash, ridiculous, too long, and in the end invigorating, the film is a grand playground for its director to fetishize old pop culture and bring his gleeful perversity to the craft of moviemaking.

"[177] Caspar Salmon of The Guardian took issue with the violence in the film, writing, "Tarantino's filmography reveals a director in search of increasingly gruesome settings to validate his revenge fantasies and...blood-thirst.

By turning the tragic Manson murders into a kind of fairytale, Tarantino uses revisionist storytelling to create a "joyride" through the darker moments of Hollywood's past, allowing characters like Dalton to find symbolic redemption amid the backdrop of a reimagined 1969.

Hart praised the revisionism when "Tarantino's version of the story unexpectedly veered away into some other, dreamlike, better world, where the monsters inadvertently passed through the wrong door and met the end they deserved."

Hart states "the artistic masterstroke" comes in the end when Tate is heard "as a disembodied voice... speaking from that alternative reality, that terrestrial paradise that evil could not enter.

He then imagines a scenario that lets him play out his violent fantasies and allows Dalton to be a hero, using a flamethrower from a film he would never actually still own but which occupies a place in Booth's memory.

Referring to the scene's allusion to Natalie Wood, she writes "the myths last, while the truth is lost in an ocean vaster than the rolling neon streets of the Hollywood of yore.

By leaving Billie's death open-ended, Romain believes Tarantino is asking, "Is Once Upon a Time... in Hollywood a touching fable about reclaiming relevance, or a horror story about a business that forgives heinous acts the second righteousness is procured?"

[211] Cliff Booth is a reference to Brad Pitt's character in Tarantino's Inglourious Basterds, Lt. Aldo Raine, a special forces WWII veteran who takes the cover of a stuntman.

[27] On the set of Batman, for a crossover episode with The Green Hornet,[219] a fight was scripted with Kato (Bruce Lee) losing to Dick Grayson's Robin (Burt Ward).

[233][234] Lee's daughter Shannon described the depiction as "an arrogant asshole who was full of hot air" and that "they didn't need to treat him in the way White Hollywood did when he was alive.

"[255] According to Tarantino, the novel is "a complete rethinking of the entire story," and adds details to various sequences and characters, including multiple chapters dedicated to the backstory of Cliff Booth.

[260]: 38:00–40:00 Also in 2019, Tarantino expressed interest in creating a Bounty Law television series based on five half-hour scripts he wrote in preparation for the film and that he plans on writing three more episodes.

[262] On August 6, 2021, the rock band Twin Atlantic released a Once Upon a Time in Hollywood-themed music video for their song "Bang On the Gong," with lead singer, Sam McTrusty taking inspiration from Rick Dalton.