Pitt was apparently unhurt and soon resumed signing autographs.
Witnesses saw the man from the fan area jump over a barrier on to the red carpet yesterday at the El Capitan Theatre in Hollywood and rush at Pitt, touching him briefly before security guards wrestled him back across the barrier.
A police spokeswoman says the man, whose name she did not know, was arrested on suspicion of battery.
Pitt kept greeting fans and walked into the theatre.
Pitt's longtime partner Angelina Jolie stars in Maleficent, Disney's new live action spin on Sleeping Beauty.