Seann William Scott, 34, has entered a non-disclosed rehab facility," his rep tells E! online.
"Scott has voluntarily admitted himself for proactive treatment to address health and personal issues," said the rep. "He appreciates the support of his many fans at this time."
The actor, 34, is best-known as Stifler -- the crude buddy from the American Pie films. Last year he co-starred with Bruce Willis and Tracy Morgan in the buddy flick, Cop Out.