Benedictus Mang Reng Say (15 June 1928 – 16 August 2003) was an Indonesian politician who was appointed Vice Chairman of the People's Representative Council of Mutual Assistance (Indonesian: Dewan Perwakilan Rakyat Gotong Royong, ) 1966–1971. In Indonesia's historical records Ben Mang Reng Say along with Frans Seda plays an important role in the Rome meeting under Foreign Minister Adam Malik and General Murtopo in order to discuss East Timor's peaceful integration into the unitary state of Indonesia territory.