Madisonville is a town in St. Tammany Parish in the U.S. state of Louisiana. The population was 748 at the 2010 U.S. census, and 850 at the 2020 U.S. census. It is part of the New Orleans–Metairie–Kenner metropolitan statistical area. The ZIP code is 70447.

Madisonville was founded by Jean Baptiste Baham in 1800, before the United States acquired this area, as the town of "Coquille" or "Cokie" because of the abundance of shells in the area, at the site of the Native American village of "Chiconcte". The town was renamed in honor of US President James Madison around 1811.

Madisonville was a notable port, providing bricks and other products of the towns along the Tchefuncte River to New Orleans, in the decades before the Civil War. After the Capture of New Orleans by the Union Army, this area remained under nominal Confederate control; and the cutoff of trade with New Orleans across enemy lines was devastating to the local economy, which did not recover for decades after the peace.

The opening of the Lake Pontchartrain Causeway and associated highways gradually brought Madisonville into the sphere of Greater New Orleans, in the second half of the 20th century.

Much of the town flooded with the Lake Pontchartrain storm surge of Hurricane Katrina, on August 29, 2005. The police/fire station and the town hall were damaged by the flood waters. The town flooded again in 2012 during Hurricane Isaac. Town buildings were again repaired but the police station was moved to a historic building at the intersection of Covington, St. John and Cedar Streets. The fire station later moved to a new building on Hwy. 22 just west of the town center.

Frederick (Fritz) Jahncke emigrated to New Orleans from Hamburg, Germany in 1870. After working as a mason, he started a business that built the first sidewalks in New Orleans. Jahncke expanded; using a rented steam-driven hydraulic suction dredge, his firm was the first to extract sand and shell from the Tchefuncte and other rivers to make concrete used in expanding New Orleans.

Jahncke purchased a half-interest in the Baham Shipyard, entering into shipbuilding. In 1905 he purchased the remaining interest, acquiring land for yards, as well as warehouses, docks, storage facilities and equipment. He died in 1911 and the company passed to Ernest Lee, Paul F. and Walter F. Jahncke. In 1917, the company started building five wooden ships for the US Navy for World War I. Two ships were completed – the SS Bayou Teche, which was launched in March 1918, and the SS Balabac on September 29, 1918. The war ended November 11, 1918, and three of the ships were not completed. The SS Abbeville was completed on January 19, 1919, and the SS Pontchartrain on April 6, 1919. The last ship was hauled across the river and burned. Part of the hull is still visible at low tide.

The Jahncke Shipyard, once a hub of shipbuilding activity during World War I, is no longer operational. While the shipyard itself is now a historical site, its legacy lives on in the maritime industry in the area. Just 2 miles downriver from the original Jahncke Shipyard site is Marina del Ray, which has grown to become the largest marina in the region, serving as a key facility for local boaters and visitors alike.

The town of Madisonville is located on the banks of the Tchefuncte River, near where the river enters Lake Pontchartrain. According to the United States Census Bureau, the town has a total area of 2.51 square miles (6.51 km), of which 2.49 square miles (6.46 km) is land and 0.02 square miles (0.06 km), or 0.86%, is water. The Tchefuncte River is a key feature of the area, offering scenic views and opportunities for boating and recreation. The best way to access the river is through local marinas and docks, with the largest and most accessible being Marina del Ray. This marina provides easy access to the river, making it a popular choice for boaters and visitors looking to explore the waterway.

Historical population

Census	Pop.	Note	%±
1870	398		—
1880	441		10.8%
1890	574		30.2%
1900	779		35.7%
1910	1,028		32.0%
1920	1,103		7.3%
1930	837		−24.1%
1940	915		9.3%
1950	861		−5.9%
1960	860		−0.1%
1970	801		−6.9%
1980	799		−0.2%
1990	659		−17.5%
2000	677		2.7%
2010	748		10.5%
2020	850		13.6%
U.S. Decennial Census

Madisonville racial composition as of 2020

Race	Number	Percentage
White (non-Hispanic)	741	87.18%
Black or African American (non-Hispanic)	38	4.47%
Native American	4	0.47%
Asian	12	1.41%
Other/Mixed	21	2.47%
Hispanic or Latino	34	4.0%

At the 2020 United States census, there were 850 people, 333 households, and 201 families residing in the town. At the 2000 United States census, there were 677 people, 302 households, and 186 families residing in the town. The population density was 277.0 inhabitants per square mile (107.0/km). There were 346 housing units at an average density of 141.6 per square mile (54.7/km). The racial makeup of the town was 85.67% White, 10.04% Black, 0.74% Native American, 0.15% Asian, 1.77% from other races, and 1.62% from two or more races. Hispanic or Latino of any race were 2.51% of the population.

There were 302 households, out of which 21.9% had children under the age of 18 living with them, 44.7% were married couples living together, 10.6% had a female householder with no husband present, and 38.4% were non-families. 31.8% of all households were made up of individuals, and 8.9% had someone living alone who was 65 years of age or older. The average household size was 2.24 and the average family size was 2.81.

In the town, the population was spread out, with 19.2% under the age of 18, 8.7% from 18 to 24, 28.8% from 25 to 44, 29.5% from 45 to 64, and 13.7% who were 65 years of age or older. The median age was 42 years. For every 100 females, there were 103.3 males. For every 100 females age 18 and over, there were 100.4 males.

The median income for a household in the town was $50,625, and the median income for a family was $57,083. Males had a median income of $41,042 versus $19,375 for females. The per capita income for the town was $25,114. About 4.5% of families and 7.2% of the population were below the poverty line, including 1.3% of those under age 18 and 17.8% of those age 65 or over.

Madisonville hosts the Lake Pontchartrain Basin Maritime Museum, which sponsors the Wooden Boat Festival each fall.

The Tchefuncte River Lighthouse is owned by the Town of Madisonville and is operated by the Lake Pontchartrain Basin Maritime Museum with a grant from the Institute of Museum and Library Services and the Southeastern Museum Conference, a gift from the Southeastern Louisiana University Development Fund that included live-streaming security cameras and on-site information about lake levels and wind and wave action by the Department of Computer Science, as well as contributions from private groups and individuals. The Tchefuncte River Lighthouse was placed on the National Register of Historic Places July 14, 1986. It is only accessible by boat. The lighthouse, visible from Marina del Ray down to the parking area at the Madisonville Boat Launch, survived Hurricanes Katrina and Rita and remains an important historical site. The lighthouse keepers' cottage was removed to the grounds of the maritime museum where it remains.

St. Tammany Parish Public School System is the public school system of the entire parish. Schools operated by the district which include Madisonville in their attendance boundaries are:

• Madisonville Elementary School (pre-kindergarten-2), north of Madisonville
• Lancaster Elementary School (grades 3 to 6), northwest of Madisonville
• Madisonville Junior High School (grades 7 and 8), inside Madisonville
• Mandeville High School (grades 9-12) in Mandeville

St. Tammany Parish Library operates the Madisonville Branch.

St. Tammany Parish is within the service areas of two community colleges: Northshore Technical Community College and Delgado Community College.

• Cag Cagnolatti, musician
• Leah Chase, chef
• John Neely Kennedy, United States Senator from Louisiana
• Irv Stein, baseball player

• Town of Madisonville official website