The 6-foot-2, 180-pounder also held offers from Oregon State and Colorado State but picked up a scholarship from the Cowboys a few days before committing.
Del Rio has seen his stock take off over the past month after he performed extremely well at Elite 11 events in Columbus and the Bay Area and was named the Columbus Nike Camp quarterback MVP. He was named a finalist to the Elite 11 in Southern California next month.
The son of former Jacksonville Jaguars head coach and current Denver Broncos defensive coordinator Jack Del Rio, the quarterback becomes Oklahoma State's eighth commitment for the class of 2013. Last fall, he passed for 2,530 yards and 20 touchdowns.
Class of 2012 quarterback commit Wes Lunt enrolled early in Stillwater and was recently named the starting quarterback.