"We've had senior pranks plenty of times," said East Paulding County High School assistant principal Greg Musgrove, "but nothing to where this much damage has been done."
The students allegedly spray-painted "seniors" and "2012" around the campus.
People passing the school Sunday spotted the suspicious activity and called authorities, The Atlanta Journal-Constitution reported.
The students were charged with criminal interference on government property, a felony, the newspaper said.
Crews worked to clean the campus before school began on Monday.