Twin cities

Tri-cities

Quad cities

More than four cities

Unincorporated communities

Even unincorporated communities, which are called "cities" in everyday conversation, can be called "twin cities" if they have a neighbor that is also unincorporated, or even a proper city.

Examples

United States

Michigan:

• Dorr, Michigan and Moline, Michigan
• Hessel, Michigan and Cedarville, Michigan
• Kinross, Michigan and Kincheloe, Michigan
• Prudenville, Michigan and Houghton Lake, Michigan
• Haslett, Michigan and Okemos, Michigan

North Carolina:

• Rodanthe, North Carolina and Salvo, North Carolina, technically a tri-city area since Waves, North Carolina sits in between those two places.

Cities sharing services

here are cities that become "twins" by sharing certain services.

• Berkley, Michigan and Royal Oak, Michigan both share the 44th district court building for legal proceedings of police citations even though Berkley has its own police department.
• Decker, Michigan has its official post office physically located in Hemans, Michigan, both actually unincorporated communities located in Lamotte Township.

Examples of cities formed by amalgamation

Asia

China

• Wuhan in China consists of the towns of Wuchang, Hankou, and Hanyang in Hubei Province.

India

• Delhi: What used to be Old Delhi, New Delhi, and a collection of smaller villages has now grown into the current megalopolis that is seen today, also known as the National Capital Region (NCR)
• In Telangana, the cities of Hyderabad and Secunderabad are merged to form Greater Hyderabad.

Japan

• Fukuoka in Japan, a city of 1.4 million people, formerly the twin cities of Hakata and Fukuoka until the late 19th century.
• Kitakyushu in Japan, a city of 900,000 people, created in 1963 by the merger of Yahata, Kokura, Moji, Wakamatsu, and Tobata. Yahata and Kokura had formerly been major cities in their own right.
• Saitama in Japan, a city of 1.2 million people, created in 2001 by the merger of the cities of Urawa, Omiya, Yono, and later Iwatsuki. Urawa and Omiya could formerly have been considered twin cities.

Pakistan

• Islamabad, the capital city of Pakistan, has been expanded to include smaller towns including Rawat in its territory.
• Lahore, the second largest city of Pakistan, has, as of 2013, grown out so much that small towns by this giant city, such as Shahdara, have been absorbed in its city limits.

Philippines

• Manila, the capital city of the Philippines, was reorganized in 1901 by merging several municipalities, including Tondo, Sampaloc, Paco, Pandacan, Ermita, and Malate, into one city when its borders were extended outside the walled city now known as Intramuros.
• Iloilo City, in the Visayas, was expanded to absorb the municipalities of Molo, La Paz, Arevalo, and Mandurriao in 1937 as districts. The nearby city of Jaro was later absorbed in 1941.

Taiwan

• The former cities of Taoyuan and Zhongli, Taiwan, which merged along with the entire county in 2014 to form a single municipality city of Taoyuan, the two cities sit directly next to each other and shares almost the same population.

Thailand

• Bangkok, the capital and largest city of Thailand, was created in 1971, when the previous Bangkok province (Phra Nakhon) was merged with Thonburi province.

Vietnam

• The cities of Saigon and Cholon merged in 1931 to form a single city named Saigon-Cholon; in 1956, the name Cholon was dropped and the city became known as Saigon (now Ho Chi Minh City).
• The city of Hà Đông, capital of Hà Tây Province was merged into Hà Nội upon the latter's amalgamation into Hà Nội in August 2008. Since then, Hà Đông became an urban district (quận) of Hà Nội.

Europe

Germany

• Berlin (Berlin and Cölln), in Germany
• Duisburg (Duisburg and Hamborn, 1929–1935 called Duisburg-Hamborn), in North Rhine-Westphalia
• Krefeld (Krefeld and Uerdingen, 1929–1940 called Krefeld-Uerdingen), in North Rhine-Westphalia
• Wuppertal (Barmen and Elberfeld), in North Rhine-Westphalia

Greece

• Athens incorporated dozens of villages and towns and absorbed whole of Athens basin and parts outside of it, notably Piraeus.

Hungary

• Budapest, Hungary is the amalgamation of Buda, Pest and Óbuda.

The Netherlands

• Eindhoven, the Netherlands, merged with five neighbouring municipalities (Woensel, Tongelre, Stratum, Gestel en Blaarthem and Strijp) into the new Groot-Eindhoven ("Greater Eindhoven") in 1920. The prefix "Groot-" was later dropped.

Spain

• Madrid, evolved by absorption of other towns (like Tetuán de las Victorias, Vallecas, Chamartín de la Rosa or Aravaca)

United Kingdom

• Edinburgh, Scotland, absorbed a number of surrounding villages, but most notably the separate burgh of Leith.
• London, grew from its cores in the City of London and the City of Westminster to encompass many other towns and villages within neighbouring counties and absorbed almost the whole of Middlesex county.
• Manchester and the city of Salford in the Metropolitan County of Greater Manchester (formerly in Lancashire).
• Stoke-on-Trent was created in 1910 from the towns of Burslem, Hanley, Tunstall, Longton, Fenton and Stoke, taking its name from the latter. Neighbouring Newcastle-under-Lyme remains a separate town.

North America

Canada

• Port Alberni, British Columbia, Canada, was formed in 1967 when Alberni and Port Alberni, merged to become one city.
• Winnipeg, Manitoba, Canada, amalgamated with 12 surrounding municipalities and its metropolitan corporation in 1971 under what was referred to as unicity reforms in local government restructuring.
• Halifax and Dartmouth, Nova Scotia, Canada, were merged in 1996 along with Bedford and Halifax County to create the Halifax Regional Municipality.
• Greater Sudbury, Ontario, Canada, was formed in 2001 by the amalgamation of the former Regional Municipality of Sudbury, comprising the municipalities of Sudbury, Nickel Centre, Valley East, Capreol, Rayside-Balfour, Onaping Falls and Walden, plus a number of previously unamalgamated townships. The amalgamation made it the most populous city in the Northern Ontario region.
• Kingston, Ontario, Canada, was amalgamated in 1998 with the neighboring Kingston and Pittsburgh Townships.
• Ottawa, Ontario, Canada, was given its large area by the amalgamation in 2001 of the old City of Ottawa, the suburbs of Nepean, Kanata, Gloucester, Rockcliffe Park, Vanier and Cumberland, Orleans, and the rural townships of West Carleton, Osgoode, Rideau, and Goulbourn
• Toronto, Ontario, Canada, formed by an amalgamation of the Old Toronto with East York, Etobicoke, North York, Scarborough and York, which were themselves products of earlier amalgamations.
• Thunder Bay, Ontario, Canada (Fort William and Port Arthur).
• Gatineau, Quebec, Canada, formed by the amalgamation of the old City of Gatineau, City of Hull, City of Aylmer, City of Buckingham and the Municipality of Masson-Angers all facing the City of Ottawa, Ontario from the north shore of the Ottawa River.
• Montreal, Quebec, Canada, was merged with the other 27 communities on the Island of Montreal by an act in the Quebec Parliament in 2002. Following a change in the provincial government, several communities later voted via referendum to de-merge and there are now a total of 15, leaving Montreal merged with the other 12.
• Saguenay, Quebec, Canada (Chicoutimi, Jonquière, et al.)
• Lloydminster, Canada, on the Saskatchewan-Alberta border, was formed as a single entity in 1903, when both future provinces were part of the Northwest Territories, but was divided into two separate entities in 1905 because the border between the newly created provinces bisected the community. In 1930, the two towns were reunited as a single town under the shared jurisdiction of both provinces, and Lloydminster was reincorporated as a single city in 1958.

United States

• Helena–West Helena, Arkansas was formed in 2006 by the merger of the previous cities of Helena and West Helena.
• Fremont, California was formed in 1956 by the combination of the five towns of Centerville, Irvington, Niles, Mission San Jose, and Warm Springs, California. The town of Newark has always refused to merge into Fremont, and Newark is completely surrounded by Fremont.
• Cahokia Heights, Illinois was formed in 2021 when the municipalities of Alorton, Cahokia, and Centreville voted in a 2020 referendum to merge.
• Boston, Massachusetts is made up of the former towns of Boston, Dorchester, Brighton, Roxbury, Charlestown, and Hyde Park.
• Iron River, Michigan absorbed the nearby city of Stambaugh and village of Mineral Hills in July 2000.
• Minneapolis, Minnesota. St. Anthony (not to be confused with St. Anthony Village, a modern city which is a suburb) was a twin city to Minneapolis in the two cities' youth. Minneapolis annexed St. Anthony in the late 1800s.
• Park Hills, Missouri was formed in 1994 by a four-way municipal merger involving the cities of Flat River, Elvins, and Esther, plus the village of Rivermines.
• Jersey City, New Jersey, was incorporated in 1820, and slowly grew by annexing surrounding municipalities: Van Vorst Twp. (1851), Bergen City (1869), Hudson City (1869), Bergen Twp. (1869) and finally Greenville Twp. (1873).
• New York City, New York (five boroughs, historically especially between Manhattan and Brooklyn)
• What is now the city of Winston-Salem, North Carolina was once two separate towns called Winston and Salem that were combined into one.
• Cleveland (Cleveland and Ohio City) in Ohio
• Lincoln City, Oregon was formed in 1965 by merging the extant seaside towns of Oceanlake, Delake, and Taft, with the adjoining unincorporated areas of Nelscott and Cutler City.
• Bethlehem, Pennsylvania, which absorbed the cities of South Bethlehem, and West Bethlehem. The former Bethlehem and South Bethlehem are situated in Northampton County, and West Bethlehem is in Lehigh County. As a result, present-day Bethlehem straddles the county line.
• Pittsburgh, Pennsylvania, annexed Allegheny City, which is now the quarter of the city that lies north of the Allegheny and Ohio rivers. Also annexed was Birmingham, now referred to as the "South Side".
• Richmond (Richmond and Manchester) in central Virginia
• Bellingham, Washington was formed from four cities, Fairhaven, Sehome, Bellingham and Whatcom.

Fictional twin cities

• Ankh-Morpork, from Terry Pratchett's Discworld novels, is referred to as "the twin cities of proud Ankh and pestilent Morpork"
• Besźel and Ul Qoma in China Miéville's novel The City & the City are intertwined twin city-states in Eastern Europe whose inhabitants have trained themselves to only see the city they live in and unsee the city they don't.
• Central City and Keystone City, from the current Flash comics, are shown as twin cities. Before the 1985-86 miniseries Crisis on Infinite Earths, Central and Keystone are presented as located in the same space but on different parallel Earths.
• Duckburg and St. Canard were depicted in the cartoon Darkwing Duck as sister cities connected by a bridge, very similar to Oakland and San Francisco.
• Gotham City (the home of Batman) and Metropolis (the home of Superman) have sometimes been presented as twin cities, mainly in 1970s and 1980s stories by DC Comics. In stories presenting them as twin cities, Gotham City and Metropolis are located on opposite sides of a large bay (identified as Delaware Bay in 1990's The Atlas of the DC Universe), with both cities linked by the Metro–Narrows Bridge, a suspension bridge resembling New York City's Verrazzano–Narrows Bridge.
• Helium, from the Barsoom series of novels by Edgar Rice Burroughs, consists of the twin cities Greater Helium and Lesser Helium.