A congress is a formal meeting of representatives from different countries (or by extension constituent states), or independent organisations (such as different trade unions).

The term Congress was chosen for the US Congress to emphasise the status of each state represented there as a self-governing unit. Subsequently to the use of congress by the US legislature, the term has been adopted by many states within unions, and by unitary countries in the Americas, to refer to their legislature, although this usage does not correspond to the proper meaning of the word.

The term Congress is often identified with the presidential system of government.

National congress

Countries with Congresses and presidential systems:

• The Congress of Guatemala (Spanish: Congreso de la República) is the unicameral legislature of Guatemala.
• The Congress of Honduras (Spanish: Congreso nacional) is the legislative branch of the government of Honduras.
• The Congress of Mexico ( ) is the legislative branch of Mexican government.
• The Congress of Paraguay is the bicameral legislature of Paraguay.
• The Congress of the Argentine Nation (Spanish: Congreso de la Nación Argentina) is the legislative branch of the government of Argentina.
• The Congress of the Dominican Republic is the bicameral legislature of the Dominican Republic.
• The Palau National Congress (Palauan: Olbiil era Kelulau) is the bicameral legislative branch of the Republic of Palau.
• The Congress of the Federated States of Micronesia is the unicameral legislature of the Federated States of Micronesia.
• The Congress of the Philippines (Filipino: Kongreso ng Pilipinas) is the legislative branch of the Philippine government.
• The Congress of the Republic of Peru (Spanish: Congreso de la República) is the unicameral legislature of Peru.
• The Congress of the United States is the bicameral legislative branch of the United States federal government.
• The National Congress of Bolivia is the national legislature of Bolivia.
• The National Congress of Brazil ( ) is Brazil's legislature.
• The National Congress of Chile (Spanish: Congreso Nacional) is the legislative branch of the government of Chile.
• The National Congress of Ecuador is the unicameral legislature of Ecuador.

Other countries with Congresses:

• In France, the congrès is a formal and exceptional joint meeting of both houses of Parliament in order to ratify an amendment to the Constitution.
• Spanish Congress of Deputies (Spanish: Congreso de los Diputados), the lower house of the Cortes Generales, Spain's legislative branch
• The legislature of the People's Republic of China is known in English as the National People's Congress. The PRC is nevertheless not a congressional system.