The famous playwright known for his works on existentialism is Samuel Beckett, notable for his innovative plays like "Waiting for Godot." Beckett's writing explores themes of absurdity, human existence, and the struggle for meaning in a seemingly indifferent world. His minimalist style and attention to language revolutionized theater, and he became a central figure in the theater of the absurd. Through ambiguous characters and non-linear narratives, Beckett's works challenge audiences to confront profound philosophical questions, solidifying his status as a major influencer in 20th-century literature.