A tripoint, trijunction, or triple point (also, if inexactly, known as a tri-border area), is a geographical point at which the borders of three countries or subnational entities meet.

There are currently 157 international tripoints (i.e., tricountry points) by some accounts, and as many as 176 (or even 207) by others, but in any case these counts include a few condominial and buffered trijunctions that are technically tri lines or tri areas rather than simply tripoints. Nearly half of these usually exact but sometimes slightly indefinite places are situated not on dry land but in rivers or lakes or seas. When on dry land, the exact tripoints are usually demarcated by the center or vertex of special (but highly various) markers or pillars. Often and increasingly such places are also the sites of sometimes extensive monumental memorials and expositions.

Usually, the more neighbours a country has, the more international tripoints that country has. China with 16 tripoints and Russia with 11 to 14 lead the list of states by number of tripoints. Within Europe, landlocked Austria has nine tripoints, among them two with Switzerland and Liechtenstein. Island countries such as the UK or Japan have no tricountry points (some, like Bahrain and Singapore, have tripoints in the territorial waters), nor have states with only one neighbour state, like Portugal or Denmark. Likewise the United States with two neighbour states has no tricountry points; it has a number of tristate points as well as one point where four states meet.

The Triple Frontier (Spanish: La Triple Frontera, Portuguese: Tríplice Fronteira) is a tri-border area along the junction of Paraguay, Argentina, and Brazil, where the Iguazú and Paraná rivers converge. Near the convergence are the cities of Ciudad del Este, Alto Paraná; Puerto Iguazú, Misiones and Foz do Iguaçu, Paraná. This area is near Iguazú Falls and the Itaipú hydroelectric plant.

The population in the Triple Frontier is concentrated in three border cities. Of these, the largest is Ciudad del Este in Paraguay, which in 2010 had a population of 390,000, while the smallest with a population of 82,000 is Puerto Iguazú, Argentina. The tourist-centric Brazilian city Foz do Iguaçu has a population of 300,000. The Arab and other Asian immigrant communities, which make up an important part of the urban population in the Tri-Border Area, are estimated to number approximately 50,000.

The Triple Frontier is an important tourist area, within the touristic subregion of the Región de las Aguas Grandes. Visitors can see the Tancredo Neves bridge, which connects the Argentine city of Puerto Iguazú and its Brazilian neighbor, Foz do Iguaçu. At the convergence of the borders, each of the three bordering countries has erected an obelisk, painted in the national colors of the country in which it is located. All three countries can be seen from each of the obelisks.