St. Martin Parish (French: Paroisse de Saint-Martin) is a parish located in the U.S. state of Louisiana. As of the 2010 census, the population was 52,160. The parish seat is St. Martinville. The parish was founded in 1811.
The parish is split into two non-contiguous parts because of a surveying error dating to 1868, when Iberia Parish was created by the Louisiana Legislature. Iberia Parish divides St. Martin Parish into two separate areas, Upper and Lower St. Martin. According to the U.S. Census Bureau, the parish has a total area of 816 square miles (2,110 km), of which 738 square miles (1,910 km) is land and 79 square miles (200 km) (9.7%) is water. St. Martin Parish is in the Atchafalaya Basin, with Bayou Teche running through it. The Bayou was used to ship products to New Orleans.
St. Martin Parish has a wealth of oak and magnolia trees.
As of the census of 2000, there were 48,583 people, 17,164 households, and 12,975 families residing in the parish. The population density was 66 people per square mile (25/km²). There were 20,245 housing units at an average density of 27 per square mile (11/km²). The racial makeup of the parish was 65.95% White, 31.98% Black or African American, 0.92% Asian, 0.29% Native American, 0.20% from other races, and 0.65% from two or more races. Hispanics or Latinos of any race made up 0.83% of the population. The 2000 census counted 44,915 people in the parish who are at least five years old of whom 31,229 (69.5%) speak only English at home, 27.44% reported speaking French (Colonial French also known as Plantation Society French ) or Cajun French at home, while 1.52% speak Louisiana Creole French. St. Martin has the highest percentage of French-speaking residents of any county or parish in the United States.
There were 17,164 households out of which 39.70% had children under the age of 18 living with them, 54.60% were married couples living together, 15.90% had a female householder with no husband present, and 24.40% were non-families. 20.70% of all households were made up of individuals and 7.90% had someone living alone who was 65 years of age or older. The average household size was 2.78 and the average family size was 3.22.
In the parish the population was spread out with 29.50% under the age of 18, 9.60% from 18 to 24, 29.60% from 25 to 44, 21.20% from 45 to 64, and 10.10% who were 65 years of age or older. The median age was 33 years. For every 100 females, there were 96.30 males. For every 100 females age 18 and over, there were 93.00 males.
The median income for a household in the parish was $30,701, and the median income for a family was $36,316. Males had a median income of $30,701 versus $18,365 for females. The per capita income for the parish was $13,619. About 18.40% of families and 21.50% of the population were below the poverty line, including 27.70% of those under age 18 and 22.10% of those age 65 or over.