List of metropolitan areas that overlap multiple countries

Here is a list of metroplexes that overlap multiple countries:

Excluded from list is:
*City-states being part of the overlap. One example of that would be Rome since Vatican City is isolated within Italy.

Between the United States and Canada

This list is from west to east:

*Vancouver, British Columbia - extends into Whatcom County, Washington
*Sault Ste. Marie, Michigan and Sault Ste. Marie, Ontario
*Port Huron, Michigan and Sarnia, Ontario areas
*Detroit, Michigan and Windsor, Ontario
*Buffalo-Niagara Falls metropolitan area, New York and St. Catharines-Niagara Falls, Ontario
*Ogdensburg-Massena, New York (St. Lawrence County) and Cornwall-Prescott, Ontario (micropolitan areas)

Between the United States and Mexico

*San Diego, California and Tijuana, Baja California
*El Centro-Calexico, California and Mexicali, Baja California
*Yuma, Arizona and San Luis Rio Colorado, Sonora
*Nogales, Arizona and Nogales, Sonora
*El Paso, Texas and Juarez, Chihuahua
*Del Rio, Texas and Acuña, Coahuila
*Eagle Pass, Texas and Piedras Negras, Coahuila
*Laredo, Texas and Nuevo Laredo, Tamaulipas
*McAllen, Texas and Reynosa, Tamaulipas
*Brownsville-Harlingen, Texas and Matamoros, Tamaulipas

In Europe

*Milan metropolitan area, Italy extends into Canton Ticino, Switzerland
*Basel metropolitan area, Switzerland extends into France and Germany
*Metropolitan Bratislava overlaps Slovakia, Hungary and Austria
*Strasbourg, France and Kehl, Germany
*Maastricht, Netherlands and Liège, Belgium and Aachen, Germany
*Copenhagen, Denmark and Malmö, Sweden
*Brăila-Galaţi (Cantemir) Metropolitan Area extends over Danube and Prut, including the Republica Moldova's urban area of Cantemir-Cahul
*Subotica, Serbia and Szeged, Hungary- urban sprawl between the 2 close cities
*Lille, France and Mouscron and Kortrijk, Belgium
*Metropolitan Geneva extends into France.
*Metropolitan Luxembourg City extends into Belgium, France, and Germany
*Iaşi Metropolitan Area extends over Prut, including cities like Ungheni from Republica Moldova
*Frankfurt/Oder of Germany and Slubice of Poland are one city divided by the river Oder
*Görlitz of Germany and Zgorzelec of Poland are one city divided by the river Nysa
*Cieszyn in Southern Poland and Český Těšín in the Czech Republic are one city divided by the Olza River
*Salzburg in Austria extends to Germany
*Gorizia in Italy and Nova Gorica in Slovenia
*Komárno in Slovakia and Komárom in Hungary
* Saarbrücken metropolitan area, Germany extends into France ( Forbach , Sarreguemines ) .

Elsewhere in the world

*Aqaba, Jordan; Eilat, Israel; and Taba, Egypt
*Rivera, Uruguay, and Santana do Livramento, Brazil
*Livingstone, Zambia, and Victoria Falls, Zimbabwe
*The city of Lome, the capital of Togo, extends over the border to Ghana
*The capital of Laos, Vientiane, spills over the Thai–Lao Friendship Bridge (Saphan Mittaphap) to Nong Khai province, Thailand
*Singapore together with Johor Bahru in Malaysia and Riau Islands in Indonesia, also called the Sijori Growth Triangle.
*Ciudad del Este in Paraguay, Foz do Iguaçu in Brazil and Puerto Iguazu in Argentina, also called Triple Frontera or the Tri Border.
*The Tres Fronteras metropolitan area of Tabatinga in Brazil, Leticia in Colombia, and Santa Rosa in Peru form a metropolitan area of nearly 100,000 people.
*The cities of Tacna, Peru, and Arica, Chile, form a combined metropolitan population of over 500,000 people.