B.J. Hunnicutt is a fictional character from the television series M*A*S*H, which aired from 1972 to 1983. He is portrayed by actor Mike Farrell and serves as a captain and surgeon in the 4077th Mobile Army Surgical Hospital during the Korean War. B.J. is known for his friendly demeanor, strong moral compass, and dedication to his patients. Introduced in the show's third season, B.J. replaces the character Trapper John McIntyre. He often provides a balance to the more cynical characters, such as Hawkeye Pierce, and emphasizes the importance of camaraderie and compassion in the midst of war.