Ho Chi Minh City (Thành phố Hồ Chí Minh), also widely known by its former name of Saigon (Vietnamese: Sài Gòn), is the largest city in Vietnam by population. It was known as Prey Nokor (Khmer: ព្រៃនគរ) prior to annexation by the Vietnamese in the 17th century. Under the name Saigon, it was the capital of the French colony of Cochinchina and later of the independent republic of South Vietnam 1955–75. On 2 July 1976, Saigon merged with the surrounding Gia Định Province and was officially renamed Ho Chi Minh City after revolutionary leader Hồ Chí Minh (although the name Sài Gòn is still widely used).

The metropolitan area, which consists of the Ho Chi Minh City metropolis, Thủ Dầu Một, Biên Hòa, Vũng Tàu, Dĩ An, Thuận An and surrounding towns, is populated by about 12 million people, making it the most populous metropolitan area in Vietnam. The city's population is expected to grow to 13.9 million by 2025. The population of the city is expanding faster than earlier predictions, and it wasn't until August 2017 that the city's Mayor, Nguyen Thanh Phong, admitted that previous estimates of 8-10 million were drastic underestimations. And the actual population (including those who have not officially registered) was estimated 13 million in 2017. The Ho Chi Minh City Metropolitan Area, a metropolitan area covering most parts of the southeast region plus Tiền Giang Province and Long An Province under planning, will have an area of 30,000 square kilometres (12,000 sq mi) with a population of 20 million inhabitants by 2020.

Ho Chi Minh City began as a small fishing village likely known as Prey Nokor, "Forest City", or perhaps Preah Reach Nokor which, according to a Khmer Chronicle meant "Royal City".The area that the city now occupies was originally forested, and was inhabited by Khmer peoplefor centuries before the arrival of the Vietnamese.

Beginning in the early 17th century, colonization of the area by Vietnamese settlers gradually isolated the Khmer of the Mekong Delta from their brethren in Cambodia proper and resulted in their becoming a minority in the delta. In 1623, King Chey Chettha II of Cambodia (1618–28) allowed Vietnamese refugees fleeing the Trịnh–Nguyễn civil war in Vietnam to settle in the area of Prey Nokor and to set up a customs house there. Increasing waves of Vietnamese settlers, which the Cambodian kingdom could not impede because it was weakened by war with Thailand, slowly Vietnamized the area. In time, Prey Nokor became known as Saigon. Prey Nokor was the most important commercial seaport to the Khmers. The loss of the city and the rest of the Mekong Delta cut off Cambodia's access to the East Sea. Subsequently, the only remaining Khmers' sea access was south-westerly at the Gulf of Thailand e.g. at Kampong Saom and Kep.

In 1698, Nguyễn Hữu Cảnh, a Vietnamese noble, was sent by the Nguyễn rulers of Huế by sea to establish Vietnamese administrative structures in the area, thus detaching the area from Cambodia, which was not strong enough to intervene. He is often credited with the expansion of Saigon into a significant settlement. A large Vauban citadel called Gia Định was built by Victor Olivier de Puymanel one of the French mercenaries of Nguyễn Ánh. The citadel was later destroyed by the French following the Battle of Kỳ Hòa

Conquered by France and Spain in 1859, the city was influenced by the French during their colonisation of Vietnam, and a number of classical Western-style buildings and French villas in the city reflect this. Saigon had, in 1929, a population of 123,890, including 12,100 French.

In 1931, a new région called Saïgon–Cholon consisting of Saïgon and Cholon was formed. Saïgon and Cholon, meanwhile, remained separate cities with their respective mayors and municipal councils. In 1956, after South Vietnam's independence from France in 1955, the région of Saïgon–Cholon became a single city called Saïgon following the merger of the two cities of Saïgon and Cholon.

The Viet Minh proclaimed the independence of Vietnam in 1945 after a combined occupation by Vichy France and Japan, and before the Communist revolution in China. They were led by Ho Chi Minh. The Viet Minh-held sections of Vietnam were more concentrated in rural areas. Following the death of Franklin Roosevelt and the abandonment of anti-colonialist policies the U.S. supported France in regaining its control over the country, with effective control spanning mostly in the Southern half and parts of the Red River Delta region like Hanoi, Haiphong and Thái Bình.

Former Emperor Bảo Đại made Saigon the capital of the State of Vietnam in 1949 with himself as head of state. In 1954, the Geneva Agreement partitioned Vietnam along the 17th parallel (Bến Hải River), with the communist Việt Minh, under Ho Chi Minh, gaining complete control of the northern half of the country, while the Saigon government continued to govern the State of Vietnam which continued in the southern half of the country and the southern half gaining independence from France. The State officially became the Republic of Vietnam when Bảo Đại was deposed by his Prime Minister Ngô Đình Diệm in 1955 in the referendum. Saigon and Cholon, an adjacent city with mostly Sino-Vietnamese residents, were combined into an administrative unit known as the Đô Thành Sài Gòn (Capital City Saigon), or Thủ đô Sài Gòn (National Capital Saigon).

South Vietnam was a capitalist and anti-communist state which fought against the communist North Vietnamese and their allies during the Vietnam War, with the assistance of the United States and other countries. The Viet Cong (formerly Viet Minh), on the other hand, was supported by the Soviet Union. On 30 April 1975, Saigon fell, ending the Vietnam War.

At the conclusion of the Vietnam War on 30 April 1975, the city came under the control of the Vietnamese People's Army. Among Vietnamese diaspora communities and particularly the U.S. (which had fought the communists), this event is commonly called the "fall of Saigon", while the Socialist Republic of Vietnam refers to it as the "Liberation of Saigon". In 1976, upon the establishment of the unified communist Socialist Republic of Vietnam, the city of Saigon (including Cholon), the province of Gia Ðịnh and two suburban districts of two other nearby provinces were combined to create Ho Chi Minh City in honor of the late Communist leader Hồ Chí Minh. The former name Saigon is still widely used by many Vietnamese, especially in informal contexts. Generally, the term Saigon refers only to the urban districts of Ho Chi Minh City.

Ho Chi Minh City is located in the south-eastern region of Vietnam, 1,760 km (1,090 mi) south of Hanoi. The average elevation is 19 metres (62 ft) above sea level. It borders Tây Ninh Province and Bình Dương Province to the north, Đồng Nai Province and Bà Rịa–Vũng Tàu Province to the east, Long An Province to the west and the East Sea to the south with a coast 15 km (9 mi) long. The city covers an area of 2,095 km2 (809 sq mi or 0.63% of the surface of Vietnam), extending up to Củ Chi District (12 mi or 19 km from the Cambodian border) and down to Cần Giờ on the Eastern Sea. The distance from the northernmost point (Phú Mỹ Hưng Commune, Củ Chi District) to the southernmost one (Long Hòa Commune, Cần Giờ District) is 102 km (63 mi), and from the easternmost point (Long Bình ward, District Nine) to the westernmost one (Bình Chánh Commune, Bình Chánh District) is 47 km (29 mi).

The city has a tropical climate, specifically a tropical wet and dry climate, with an average humidity of 78–82%. The year is divided into two distinct seasons. The rainy season, with an average rainfall of about 1,800 millimetres (71 in) annually (about 150 rainy days per year), usually begins in May and ends in late October. The dry season lasts from December to April. The average temperature is 28 °C (82 °F), with little variation throughout the year. The highest temperature recorded was 40.0 °C (104 °F) in April while the lowest temperature recorded was 13.8 °C (57 °F) in January. On average, the city experiences between 2,400 to 2,700 hours of sunshine per year.

With a population now of 8,382,287 (as of Census 2010 on 1 April 2010) (registered residents plus migrant workers as well as a metropolitan population of 10 million), Ho Chi Minh City needs increased public infrastructure. To this end, the city and central governments have embarked on an effort to develop new urban centres. The two most prominent projects are the Thu Thiem city centre in District 2 and the Phu My Hung Urban Area, a new city centre in District 7 (as part of the Saigon South project) where various international schools such as Saigon South International School and Australia's Royal Melbourne Institute of Technology are located. In December 2007, Phu My Hung's new City Centre completed the 17.8 km 10–14 lane wide Nguyen Van Linh Boulevard linking the Saigon port areas, Tan Thuan Export Processing Zone to the National Highway 1 and the Mekong Delta area. In November 2008, a brand new trade centre, Saigon Exhibition and Convention Centre, also opened its doors. Other projects include Grandview, Waterfront, Sky Garden, Riverside and Phu Gia 99. Phu My Hung's new City Center received the first Model New City Award from the Vietnamese Ministry of Construction.

Ho Chi Minh City is the economic center of Vietnam and accounts for a large proportion of the economy of Vietnam. Although the city takes up just 0.6% of the country's land area, it contains 8.34% of the population of Vietnam, 20.2% of its GDP, 27.9% of industrial output and 34.9% of the FDI projects in the country in 2005. In 2005, the city had 4,344,000 labourers, of whom 130,000 are over the labour age norm (in Vietnam, 60 for male and 55 for female workers).[41] In 2009, GDP per capita reached $2,800, compared to the country's average level of $1,042

As the international tourist statistic, Ho Chi Minh City welcomed 6 million tourists in 2017.Like many of Vietnam's smaller cities, the city boasts a multitude of restaurants serving typical Vietnamese dishes such as phở or rice vermicelli. Backpacking travellers most often frequent the "Western Quarter" on Phạm Ngũ Lão Street and Bùi Viện Street, District 1.Aside from the Municipal Theatre, there are other places of entertainment such as the Bến Thành theatre, Hòa Bình theatre, and the Lan Anh Music Stage.

Ho Chi Minh City is home to hundreds of cinemas and theatres, with cinema and drama theatre revenue accounting for 60–70% of Vietnam's total revenue in this industry. Unlike other theatrical organisations found in Vietnam's provinces and municipalities, residents of Ho Chi Minh City keep their theatres active without the support of subsidies from the Vietnamese government. The city is also home to most of the private film companies in Vietnam.The city has various museums including the Ho Chi Minh City Museum, Museum of Vietnamese History, the Revolutionary Museum, the Museum of south-eastern Armed Forces, the War Remnants Museum, the Museum of Southern Women, the Museum of Fine Arts, the Nha Rong Memorial House, and the Ben Duoc Relic of Underground Tunnels. The Củ Chi tunnels are north-west of the city in Củ Chi District. The Saigon Zoo and Botanical Gardens, in District 1, dates from 1865. The Đầm Sen Tourist and Cultural Park, Suối Tiên Amusement and Culture Park, and Cần Giờ's Eco beach resort are three recreational sites inside the city which are popular with tourists.It was approximated that 4.3 million tourists visited Vietnam in 2007, of which 70 percent, approximately 3 million tourists, visited Ho Chi Minh City.

Today, the city's core is still adorned with wide elegant boulevards and historic French colonial buildings. The majority of these tourist spots are located in District 1 and are a short leisurely distance from each other. The most prominent structures in the city centre are the Reunification Palace (Dinh Thống Nhất), City Hall (Ủy ban nhân dân Thành phố), Municipal Theatre (Nhà hát thành phố, also known as the Opera House), City Post Office (Bưu điện thành phố), State Bank Office (Ngân hàng nhà nước), City People's Court (Tòa án nhân dân thành phố) and Notre-Dame Cathedral (Nhà thờ Đức Bà). Some of the historic hotels are the Hotel Majestic, dating from the French colonial era, and the Rex and Caravelle hotels are former hangouts for American officers and war correspondents in the 1960s & '70s.