Koji Wakamatsu (????, Wakamatsu Koji, 1 April 1936 – 17 October 2012) was a Japanese film director who directed such pinku eiga films as Ecstasy of the Angels (?????, Tenshi no Kokotsu, 1972) and Go, Go, Second Time Virgin (??????????, Yuke Yuke Nidome no Shojo, 1969).
He also produced Nagisa Oshima's controversial film In the Realm of the Senses (1976).
He has been called "the most important director to emerge in the pink film genre," and one of "Japan's leading directors of the 1960s."His 2010 film, Caterpillar, was nominated for the Golden Bear at the 60th Berlin International Film Festival.