Green-Beckham was initially connected to a possible transfer to OU last month.
The waiver is not without precedent, as LSU basketball player Anthony Hickey recently received a waiver allowing him to play immediately at Oklahoma State.
In two seasons with the Tigers, Green-Beckham had 87 catches for 1,278 yards and 17 touchdowns.
In the SEC title game against Auburn, Green-Beckham had six catches for 144 yards and two touchdowns.
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