The Constituent Assembly of Colombia (Spanish: Asamblea Nacional Constituyente de Colombia) was formed on February 5, 1991, to draft the Colombian Constitution of 1991. It was dissolved in July 1991, after the new document was adopted nationwide.

Throughout the later half of the 20th century, many different sectors of Colombian public and political opinion, both outside and inside the Colombian Conservative Party and the Colombian Liberal Party, had developed an increasing desire to extensively reform the nation's aging 1886 constitution into a more modern document, according to the changing needs and realities of the citizens and their context, as well as a way to curb ongoing violence.

Some felt that the previous constitution, in spite of several amendments that had been implemented (in 1910, for example), was no longer applicable as a whole and had to be discarded in favor of a more progressive document. Others recognized that despite the presence of what they saw as some enduring positive qualities and values (such as the open proclamation of Colombia as a Catholic nation, considered as essential by some), a greater degree of political pluralism and civil liberties was still necessary in order to better address the country's problems. Apparently only a relatively small number opposed any modifications outright.

In addition to all this, many critics felt that the country was exhausted of and needed a respite from what some called the "old political class", and that a new constitution would be of use in achieving that scenario.

Despite a generally positive attitude towards change among the population, most of the early attempts to call for an extensive amendment of the existing constitution (notably in 1957, under General Gustavo Rojas Pinilla) or to convoke a Constituent Assembly ultimately failed because of different types of political and congressional infighting, but the aspiration never disappeared entirely.

In particular, during the 1980s, as several rocky peace negotiations were carried out with guerrilla groups, such as the 19th of April Movement and the EPL, the desire to change the constitution as part of the potential peace agreements began to gradually become part of a wide national consensus.

After the murder of Luis Carlos Galán in 1989 (and later those of Bernardo Jaramillo and Carlos Pizarro in early 1990) and his replacement as the Liberal presidential candidate by César Gaviria, a civic movement made up of different academic and student sectors, some of which had backed the former candidate, eventually proposed that a nonbinding "seventh ballot" (séptima papeleta) should be included in the March 1990 legislative elections, asking the electorate to pronounce itself in favor or against the future convocation of a National Constituent Assembly.

This proposal was tacitly accepted by the government of president Virgilio Barco Vargas and when an informal count of the votes was authorized by the electoral authorities, some two million voters had voted in favor of the initiative by turning in their "seventh ballots".