The youth was being held at Orange County Juvenile Hall on suspicion of assault on a peace officer, inciting a riot and refusing to follow police orders to disperse, according to the Huntington Beach Police Department.
Department officials said the youth was arrested Thursday and is a resident of Huntington Beach. They declined to identify him because he is a minor.
Seven people were arrested Sunday after about 250 police officers swooped down on Main Street as rowdy crowds rampaged in the downtown area.
People set fires in the street, toppled portable toilets and smashed windows. Several fights broke out as looters grabbed items from stores, according to police.
Two photos went viral after the incident -- one showing a man smashing the front window of the Easyrider Bike Shop with a stop sign and another showing the same man shouting with his arms in the air.
Those who shared the images on social media indicated they did so in hopes of identifying the person responsible.