Iwan Martua Lokot Dongan Simatupang, more commonly known as Iwan Simatupang (18 January 1928 in Sibolga, North Sumatra – 4 August 1970 in Jakarta, Indonesia) was an Indonesian novelist, poet and essayist.

[1] He joined the Indonesian Student Army [id] (TRIP), becoming a Commander, and was captured in North Sumatra during Operation Kraai, against the Republic of Indonesia's temporary capital in Yogyakarta (1948/49).

[2][3] He worked as a high school teacher in Surabaya, also serving as editor of Siasat (Strategy) magazine, and the Warta Harian (Daily News) (1966–1970).

In 1963, he won second prize from Sastra (Literature) magazine for his essay "Kebebasan Pengarang dan Masalah Tanah Air" (Writers' Freedom and the Problems of the Motherland).

[2] According to Benedict Anderson, Iwan Simatupang and Putu Wijaya were the two "genuinely distinguished fictionalists" produced by Indonesia since Independence and both had a strong attachment to "magical realism".