**John Castle** (born 1940) is a British actor, known for his portrayal of intelligent and complex characters, often with a vein of cynicism or moral ambiguity. His film career is marked by roles in historical dramas and prestigious productions.

His most iconic role is that of Geoffrey Plantagenet in the celebrated *The Lion in Winter* (1968), where he excelled in portraying a cunning and deeply multifaceted character. He also starred in *Man of La Mancha* (1972) and *Nijinsky* (1980), playing cerebral figures. In subsequent years, he also took on antagonist roles, such as in *RoboCop 3* (1993). His acting style is characterized by controlled intensity and precision in characterization, making him suitable for roles requiring psychological depth.