The Constitutional Assembly (Indonesian: Konstituante) was a body elected in 1955 to draw up a permanent constitution for the Republic of Indonesia. It sat between 10 November 1956 and 2 July 1959. It was dissolved by then President Sukarno in a decree issued on 5 July 1959 which reimposed the 1945 Constitution.

On 17 August 1945, Sukarno proclaimed the independence of the Republic of Indonesia. The next day, a meeting of the Preparatory Committee for Indonesian Independence chaired by President Sukarno officially adopted the Constitution of Indonesia, which had been drawn up by the Investigating Committee for Preparatory Work for Independence in the months leading up to the Japanese surrender. In a speech, Sukarno stated that the constitution was "a temporary constitution... a lightning constitution", and that a more permanent version would be drawn up when circumstances permitted.

It was not until 1949 that the Netherlands formally transferred sovereignty to Indonesia, and the United States of Indonesia was established. On 17 August the following year, this was dissolved and replaced by the unitary state of the Republic of Indonesia, with Sukarno at its head. Article 134 of the Provisional Constitution of 1950 stated, "The Constitutional Assembly together with the government shall enact as soon as possible the Constitution of the Republic of Indonesia which shall replace this Provisional Constitution."

The supreme body within the assembly, with the authority to make decisions concerning the constitution and matters related to it was the plenary session. Other parts of the assembly were components of it and answered to it. It had to convene at least twice a year, and was obliged to meet if deemed necessary by the Constitution Preparation Committee at a written request from at least a tenth of the membership. Meetings had to be open to the public unless at least 20 members requested otherwise. There were 514 members, one per 150,000 Indonesian citizens. A two-thirds majority was required to approve a permanent constitution

The assembly was led by a speaker and five deputy speakers elected from the membership. The Constitution Preparation Committee represented all the groupings within the assembly, and was tasked with drawing up proposals for the constitution to be debated by the plenary session. Below this committee was the constitutional committee, which had the power to establish commissions made up of at least seven members according to need to discuss various aspects of the constitution, and other committees to discuss other specific issues.

Elections for the Constitutional Assembly were held in December 1955, but the assembly only convened in November 1956. There were a total of 514 members, with the composition broadly reflecting that of the People's Representative Council, the elections to which had produced very similar results. Like the legislature, no party had an overall majority, and the four largest parties were the Indonesian National Party (Partai Nasional Indonesia), the Masjumi, Nahdatul Ulama and the Indonesian Communist Party (Partai Komunis Indonesia). There were a total of 34 factions represented, divided into three blocs, according to the final form of the Indonesian state they wanted to see.

The Assembly met in the Gedung Merdeka in Bandung, which had been used for the 1955 Asian-African Conference. There were a total of four sessions.

On 9 November 1956, the members elected to the Constitutional Assembly took their oaths of office, and the following day the Assembly was officially inaugurated by President Sukarno, who gave a speech a permanent constitution. Wilopo of the PNI was elected speaker, and Prawoto Mangkusasmito (Masjumi), with Fatchurahman Kafrawi (NU), Johannes Leimena (Parkindo), Sakirman (PKI) and Hidajat Ratu Aminah (IPKI) as deputy speakers.