Ok. . . maybe not every actor. When I did home care, one of the clients watched Westerns all day. I watched about every Western ever made. It was amazing to see how many actors and actresses have appeared in Westerns. There were two that surprised me. I think I was surprised because I never thought of them playing anything except the characters that they are known for.
Leonard Nimoy appeared in several television shows, such as Bonanza and Rawhide. He wasn’t always a cowboy. Nimoy played several characters with different ethnic backgrounds.
Margaret Hamilton, also known as The Wicked Witch of the West, had roles in westerns on television and movies. She was in “The Ox-bow Incident” with Henry Fonda. Although, it’s not as well known, it’s a great movie.
The only actor that I haven’t seen in a western is George Clooney. Westerns might not be his thing. It’s not for everyone.