Jun Tosaka (戸坂 潤 Tosaka Jun, 27 September 1900 – 9 August 1945) was a Shōwa era Japanese intellectual, and teacher. He was born in Tokyo in 1900. He attended Kyoto Imperial University. He was interested in Nishida Kitaro, and Tanabe Hajime, neo-Kantianism, and then Marxism. He was a member of the Kyoto School. In 1938, he was arrested under the Peace Preservation Law. He died in Nagano Prison before the end of World War II.