Celebs You Totally Forgot Guest-Starred on 'Grey's Anatomy'

Leslie Odom Jr.

Season: 5
The Harriet actor played P.J. Walling, whose dad needs a kidney. P.J. gets involved in a domino kidney transplant when his dad offers him $10,000.

Bellamy Young

Season: 3
The Prodigal Son actress played Kathy, who repeatedly visits the hospital for different injuries. She reveals that she works out in order to keep herself from cheating on her husband, whom she hasn’t been intimate with in over a year. He ends up having a tumor.