The guy caught on video smashing people over the head with a folding chair in that riverfront brawl in Montgomery, Alabama has just been arrested.
The Montgomery Police Department announced Friday that Reggie Ray turned himself in ... and he's been charged with disorderly conduct and is being held in the Municipal Jail.
TMZ obtained the 42-year-old's mug shot ... and he doesn't look happy about the consequences of his actions in the epic melee.
Ray is the fifth person arrested for the brawl ... remember, Chief of Police Darryl Albert previously identified Reggie as the Black man who infamously wielded the chair on the dock, bonking several people on the head.
Ray got in on the action late, after men from a pontoon boat that was blocking a passenger ferry from docking ganged up on the ferry's co-captain ... sparking a huge brawl along racial lines.
The other 4 arrested include Allen Todd, 23, and Zachary Shipman, 25, who turned themselves in Wednesday and are each charged with one count of 3rd degree assault.