Prawoto Mangkusasmito (4 January 1910 – 24 July 1970) was an Indonesian politician who served as the final chairman of the Masyumi political party before its dissolution in 1960.

Due to other Masyumi leaders' involvement in the Revolutionary Government of the Republic of Indonesia, Prawoto took over its leadership in 1959, unsuccessfully attempting to recover the party's political position before its dissolution in 1960.

[5] After the conclusion of the Indonesian National Revolution and the dissolution of the United States of Indonesia, he became a member of the Provisional People's Representative Council.

[6] In 1952, following the collapse of the Sukiman Cabinet, Prawoto was appointed by President Sukarno alongside the Indonesian National Party (PNI)'s Sidik Djojosukarto to form a parliament.

Due to political friction between Prawoto and PNI, however, no cabinets were formed by the pair – ministerial appointments were a matter of dispute between the two parties.

[9] Several important Masyumi leaders such as Mohammad Natsir, Burhanuddin Harahap, and Sjafruddin Prawiranegara left Jakarta for Sumatra in late 1957, and in early 1958 the remainder of the party was in crisis due to their involvement within the emerging Revolutionary Government of the Republic of Indonesia (PRRI).

His opposition, led by former prime minister Soekiman Wirjosandjojo, favored forming an anti-communist front with PNI and other nationalist parties.

Prawoto conducted negotiations with PNI to secure Masyumi's political future and made some headway, but this fell apart following Sukarno's 1959 Decree which dissolved the Constitutional Assembly.

[12] Throughout 1959 and early 1960, Sukarno further centralized power, issuing a decree that allowed the government to dissolve political parties in December 1959 and disbanding the parliament elected in 1955 in March 1960.