Siauw Giok Tjhan (; March 23, 1914 – November 20, 1981) was a Chinese Indonesian activist and politician. Born in Kapasan, Surabaya, East Java, Indonesia, he was a cabinet minister under Indonesia president Sukarno and was imprisoned for 12 years by the subsequent president, Suharto. He was active in rights campaigning and was part of Baperki, including as the group's leader. He supported the Communist takeover of China, opposed to Taiwan, and was a Marxist.