A constituent assembly (also known as a constitutional convention, constitutional congress, or constitutional assembly) is a body assembled for the purpose of drafting or revising a constitution. Members of a constituent assembly may be elected by popular vote, drawn by sortition, appointed, or some combination of these methods. Assemblies are typically considered distinct from a regular legislature, although members of the legislature may compose a significant number or all of its members. As the fundamental document constituting a state, a constitution cannot normally be modified or amended by the state's normal legislative procedures in some jurisdictions; instead a constitutional convention or a constituent assembly, the rules for which are normally laid down in the constitution, must be set up. A constituent assembly is usually set up for its specific purpose, which it carries out in a relatively short time, after which the assembly is dissolved. A constituent assembly is a form of representative democracy.
Unlike forms of constitution-making in which a constitution is unilaterally imposed by a sovereign lawmaker, the constituent assembly creates a constitution through "internally imposed" actions, in that members of the constituent assembly are themselves citizens, but not necessarily the political leaders, of the country for which they are creating a constitution. As described by Columbia University Social Sciences Professor Jon Elster:
"Constitutions arise in a number of different ways. At the non-democratic extreme of the spectrum, we may imagine a sovereign lawgiver laying down the constitution for all later generations. At the democratic extreme, we may imagine a constituent assembly elected by universal suffrage for the sole task of writing a new constitution. And there are all sorts of intermediate arrangements."