West Palm Beach police released the video Monday, showing what happened to Pablo Gilberto Valenzuela, 42, on May 26. He suffered a broken jaw and bruised eyes, authorities said.
Kurt Graham, a new officer still on probation, resigned July 22.
City spokesman Chase Scott said the two other officers, Louis Schwartz and Jason Zangara, were dismissed Tuesday after an internal investigation.
He said the police department has "a zero tolerance policy for use of excessive force."
The president of the Palm Beach County Patrolmen's Benevolent Association, the union representing the officers, told CBS station WPEC in West Palm Beach that the officers didn't deserve to be fired.
"I don't think they should be fired," PBA President John Kazanjian told WPEC. "We'll take it to arbitration if we have to."
A telephone call to an L. Schwartz in West Palm Beach rang unanswered. No telephone listings could immediately be found for Zangara or Graham.
According to the city, Schwartz attempted to arrest Valenzuela for robbing a pharmacy of about 1,000 Oxycontin pills.
The officer was involved in an unrelated traffic stop in the pharmacy parking lot when a clerk ran out of the store and said they'd been robbed, he said.
He said Schwartz caught the masked suspect behind the store, where Valenzuela attempted to pepper-spray him.
Schwartz drew his gun and ordered Valenzuela to the ground.
The video shows Graham arrive and put a knee into Valenzuela's back as he was being handcuffed. The video then shows Graham punch and kick Valenzuela in the face. Schwartz is also seen on the video kicking Valenzuela.
Zangara, the third officer, then lifted a handcuffed Valenzuela to his feet. As the suspect pulls away from the officer, Zangara can be seen punching him several times in the face until the man collapsed.
Valenzuela was arrested on charges of robbery, assault and battery on a law enforcement officer and resisting arrest.
Graham and Schwartz insist they only kicked Valenzuela because the man was trying to bite Graham's leg. Zangara said he punched Valenzuela after he tried to spit on him.
Schwartz and Zangara had been on administrative leave since around the time of the incident.