Little Saigon is a name given to any of several overseas Vietnamese immigrant and descendant communities outside Vietnam, usually in the United States. Saigon is the former name of the capital of the former South Vietnam, where a large number of first-generation Vietnamese immigrants originate.

The well-established and largest Vietnamese-American enclaves, not all of which are called Little Saigon, are located in Orange County, California; San Jose; and Houston, Texas. Somewhat smaller communities also exist, including the comparatively nascent Vietnamese commercial districts in San Francisco, San Diego, Sacramento, and Orlando.

Orange County

The oldest, largest, and most prominent Little Saigon is in Westminster and Garden Grove in Orange County, California, where Vietnamese Americans constitute 30.7% and 21.4% of the population, respectively, as of the 2000 Census. Whereas ethnic Vietnamese are predominant in this population, in many cases, the population also consists of some people of Chinese Vietnamese origin, many of whom arrived during the second refugee wave in 1980 and own a large share of businesses in Little Saigon today. Despite the title "Little Saigon," there are also many Hispanic and remaining white residents as well as some Cambodian and Laotian immigrants residing in the area.

Phước Lộc Thọ, known in English as Asian Garden Mall, the first Vietnamese-American business center in Little Saigon, Orange CountyAbout 50 miles north of Camp Pendleton, Westminster was once a predominantly white middle-class suburban city of Orange County with ample farmland, but the city later experienced a decline by the 1970s. Since 1978, the nucleus of Little Saigon has long been Bolsa Avenue, where early pioneers Danh Quach and Frank Jao established businesses. During that year, the well-known Nguoi Viet Daily News also began publishing from a home in Garden Grove. Other new Vietnamese-American arrivals soon revitalized the area by opening their own businesses in old, formerly white-owned storefronts, and investors constructed large shopping centers containing a mix of businesses. The Vietnamese community and businesses later spread into adjacent Garden Grove, Stanton, Fountain Valley, Anaheim, and Santa Ana.

In 1988, a freeway offramp sign was placed on the Garden Grove Freeway (State Route 22) designating the exits leading to Little Saigon.

Bolsa Avenue in Westminster's eastern neighbor, Santa Ana, has also been designated a Little Saigon, but there are fewer businesses in the area than in either Westminster or Garden Grove. In 2003, some controversies emerged in Santa Ana over a proposed Little Saigon sign to promote its burgeoning Vietnamese commercial area with a design incorporating Vietnamese translation and a South Vietnamese flag. The sign was approved, but redesigned and placed on Euclid Avenue and First Street.

The year 1987 saw an increase in Vietnamese-American street gang activity, as Westminster police reported an increase of extortion targeting small Vietnamese immigrant businesses. However, according to the Morgan Quitno annual study on the safety of individual US cities, both Garden Grove and Westminster are both safer than most US cities.