Pitt was apparently unhurt and, along with fiancée Angelina Jolie, who stars in the film, soon resumed signing autographs.
"[Brad] was fine, unharmed and went about his evening and watched the movie with his family," a source told PEOPLE. Maleficent is Disney's new live-action spin on its animated classic Sleeping Beauty.
Reports identified the man as Vitalii Sediuk, a Ukrainian TV presenter notorious for red-carpet incidents like putting his head up America Ferrera's dress in Cannes earlier this month.
Witnesses saw him jump over a barrier in the fan area onto the red carpet at the El Capitan Theatre and rush at the star, making brief contact before security guards wrestled him back across the barrier.
Sediuk was led away in handcuffs and arrested on suspicion of battery, said Los Angeles police spokeswoman Nuria Venegas, who confirmed that he made contact with Pitt.
In 2012, Sediuk was slapped by Will Smith when he attempted to kiss the actor on the red carpet at the Moscow premiere of Men in Black 3.
The following year, he spent the night in an L.A. jail after storming the stage as Adele accepted the award for best pop solo performance at the 2013 Grammys.
Sediuk gained access to Pitt despite security that was heavy for a movie premiere. A Disney spokesperson tells PEOPLE, "This was an unfortunate and inappropriate incident that is being investigated by the LAPD."
The couple didn't let the incident put a damper on the night, continuing to greet and sign autographs for fans. Then a cheerful Jolie made her way down a long press line, chatting with nearly every reporter while Pitt ducked into the theater, where some of the couple's children were waiting to watch the movie.
"I had to not take myself so seriously," Jolie said of taking on the role of the scheming sorceress. Asked what should be the next live-action Disney film, she replied, "You'd have to ask my kids! They know better than me."
Jolie's father, Jon Voight, was also at the premiere, and told PEOPLE he was looking forward to seeing granddaughter Vivienne, 5, make her movie debut as the young Princess Aurora.
"It's going to be exciting for me to see her face as she watches her performance," he said, and to see Zahara, 9, and Pax, 10, onscreen in cameos.
As for whether or not they will grow up to become actors, Voight said, "It's much too early now to tell about that, but they'll be encouraged whatever their dream is. Maybe some of them will go that way, who knows."
Additional reporting by ASSOCIATED PRESS