See Grey’s Anatomy’ Cast Transformations from season 1 to 18

Patrick Dempsey is one of TV most bliss stars when he was cast as Dr. Derek Shepherd, a.k.a. McDreamy. He was in series from season 1 to season 11. He returned in season 17.

Sandra Oh played Dr. Cristina Yang from season 1 until season 10. Sandra was nominated for a number of Golden Globes and Emmys for her portrayal of Cristina. 

Chandra Wilson is one of the original cast members who is still on ‘Grey’s Anatomy.’ She’s played the legendary Dr. Miranda Bailey since pilot episode.

Justin Chambers cast as Dr. Alex Karev from season 1 until season 16. In season 16 he announced his departure from show and Alex went off to be with Izzie and their twins.

Katherine Heigl’s Dr. Izzie Stevens was on the show from season 1 until season 6 and won the Primetime Emmy Award for Outstanding Supporting Actress in a Drama Series in 2007.

Giacomo Gianniotti started playing Dr. Andrew DeLuca in season 11. He has been a series regular since season 12. 

Giacomo Gianniotti started playing Dr. Andrew DeLuca in season 11. He has been a series regular since season 12. 

Kevin McKidd has played Dr. Owen Hunt since season 5. In addition to being a series regular and he has directed a number of episodes. 

Kim Raver started playing Dr. Teddy Altman in season 6 but left after 3 seasons and then returned in season 14. She has been a series regular ever since