Pidgeon continued playing ever larger roles in films of increasing importance as the 30s progressed and finally made it to full-fledged star status in middle age at the beginning of the 40s. He is best known for his roles as the dashing would-be assassin of Hitler in Fritz Lang's spy adventure, "Man Hunt" (1941); Maureen O'Hara's suitor in John Ford's "How Green Was My Valley" (1941); and for his eight co-starring efforts opposite the genteel and dignified but spirited Greer Garson. The pair were a leading box-office attraction at MGM through the 40s, best known for the English WWII melodrama "Mrs. Miniver" (1942) and the biographical "Madame Curie" (1943).
Pidgeon continued to play leading roles through the 50s and kept busy in his later years in prominent supporting parts, often with star billing. He was especially memorable as the Prospero figure in "Forbidden Planet" (1956), the engaging sci-fi feature revamp of Shakespeare's "The Tempest", and was a standout among the remarkable cast peopling Otto Preminger's political drama, "Advise and Consent" (1962). Pidgeon also appeared as Florenz Ziegfeld in "Funny Girl" (1968) and continued in films with decreasing frequency through the 70s.
Pidgeon's TV credits date back to the mid-50s when he hosted the "M-G-M Parade" (ABC, 1955-56), a variety series that offered a behind-the-scenes look at the film studio. He was featured in several high-profile TV specials from the late 50s through the mid-60s, notably playing the King in the 1965 "Cinderella" starring Lesley Ann Warren. Pidgeon began appearing in TV-movies in the late 60s, generally in character roles, and continued to do so fairly regularly through the mid-70s.