Coach Mike Riley announced Saturday that the 6-foot-2, 203-pound Del Rio, the son of Denver Broncos defensive coordinator Jack Del Rio, signed a financial aid agreement at his new school.
"We are very excited that Luke has chosen to join the Oregon State Football program," Riley said in a statement. "He is an exceptional young man and will be a great representative of Beaver Nation on and off the field."
Del Rio redshirted last season and will have to sit out a year before being eligible to play three seasons.
ESPN rated Del Rio as the No. 27 pocket passer and No. 2 player in Colorado out of high school.