The star, who previously won an Academy Award for his production of 12 Years a Slave in 2014, began by poking fun at co-star Leonardo DiCaprio, who was nominated for Best Actor for the film this year.
"Leo, I'll ride on your coattails any day, man. The view's fantastic," he quipped, before getting serious.
He then launched into a tribute to writer and director Quentin Tarantino, whom he called truly unique. Brad also gave a shoutout to Mike Moh, who plays Bruce Lee in Once Upon a Time... in Hollywood, praising his work.
"While we're doing this, I think it's time we give a little love to our stunt coordinators and our stunt crews," he said, before realizing that he was standing up on the stage at the Oscars accepting an acting award.
"Listen, I'm a bit gobsmacked," he said, and then adorably recapped just how far he's come in his acting career. "I'm not one to look back, but this has made me do so. And I think of my folks taking me to the drive trough to see Butch [Cassidy] in Sundance, and loading up my car and moving out here, to Geena and Ridley [Davis and Scott for Thelma & Louise] for giving me my first shot, to all the wonderful people I've met along the way to stand here now. Once Upon a Time... in Hollywood. Ain't that the truth."
Sweetly, he paid tribute to his six children: Zahara, Maddox, Shiloh, Pax, Knox and Vivienne.
"This is for my kids, who colour everything I do. I adore you," he finished, before leaving the stage.