Rainer Werner Fassbinder (German: [ˈʁaɪnɐ ˈvɛʁnɐ ˈfasbɪndɐ] (listen); 31 May 1945 – 10 June 1982), sometimes credited as R. W. Fassbinder, was a German filmmaker. He is widely regarded as one of the major figures and catalysts of the New German Cinema movement. Fassbinder's main theme was the exploitability of feelings. His films were deeply rooted in post-war German culture: the aftermath of Nazism, the German economic miracle, and the terror of the Red Army Faction. Other prominent themes in his films include love, friendship and more generally, the throes of interpersonal relationships, or as he put it: "the exploitability of feelings".

His first feature-length film was a gangster movie called Love Is Colder Than Death (1969); he scored his first domestic commercial success with The Merchant of Four Seasons (1972) and his first international success with Ali: Fear Eats the Soul (1974), both of which are considered masterpieces by contemporary critics. Big-budget projects such as Despair (1978), Lili Marleen and Lola (both 1981) followed. His greatest success came with The Marriage of Maria Braun (1979), chronicling the rise and fall of a German woman in the wake of World War II. Other notable films include the lesbian chamber drama The Bitter Tears of Petra von Kant (1972), Fox and His Friends (1975), Satan's Brew (1976), In a Year with 13 Moons (1978), and Querelle (1982), all of which dealt with homoerotic themes.

Fassbinder died on 10 June 1982, at age 37, from a lethal cocktail of cocaine and barbiturates. His career lasted less than two decades, but he was extremely prolific; he completed over 40 feature films, two television series, three short films, four video productions, and 24 plays, winning 5 of the most prestigious prizes for feature film in Germany, including the Golden Bear and multiple German Film Awards. His premature death is often considered the end of the New German Cinema timeframe.