The junior receiver, who caught 83 passes for 1,343 yards and 10 touchdowns this season, announced Monday that he's forgoing his senior season to turn pro.
Richardson was voted first-team all-conference in the Pac-12 on Monday. He ranked second in the conference in receptions per game and yards receiving per game.
Richardson was named the Buffaloes' MVP at their annual banquet Sunday, the first junior to win the honor in 11 years and just the sixth receiver to win the award since it was created in 1959.
He set 20 school receiving records.