David Jones had been charged with failure to report child abuse. A teacher at Jamie's House Charter School was fired when a cell phone video that caught her beating a 13-year-old student in class was made public.
Jones' attorney, William Stradley, says the principal was acquitted in 10 minutes by a jury Thursday after a two-day trial.
Stradley says Jones did not know about the serious nature of the incident until the video became public.
The teacher pleaded no contest in April to a charge of injury to a child under 15. She was given probation.
Two others charged await trial.