The actors, who worked with Perry on Quentin Tarantino's new comedy, "Once Upon a Time in Hollywood," reveal in the cover story of Esquire's Summer 2019 issue that they fanboyed hard when they met the former "Beverly Hills, 90210" star on the movie's set.
"'That’s Luke f------ Perry!'" Pitt, 55, recalled thinking. "We were like kids in the candy shop because I remember going to the studios and ('90210') was going on and he was that icon of coolness for us as teenagers."
"It was this strange burst of excitement that I had, to be able to act with him," Pitt added.
Oscar winner DiCaprio, 44, had a similar reaction.
"I remember my friend Vinny (Laresca), who is in the film as well, we walked in and we both had this butterfly moment of like, 'Oh my God, that’s Luke Perry over there!'" he shared.
During their time together on the movie's set, Pitt grew to admire Perry both personally and professionally.
"Man, he was so incredibly humble and amazing and absolutely committed. He couldn’t have been a more friendly, wonderful guy to spend time with," Pitt said of the late star, who died in March at age 52.
"I got to sit down and have some wonderful conversations with him," Pitt added. "It was really special."