Jennings is a city in St. Louis County, Missouri, United States.

[4] The city was named after James Jennings, a farmer and merchant who moved to the area from Virginia with his family and retinue of slaves in 1839.

Apparently the first commercial concern originating in the area was the Seed Dry Plate Company in 1883, which left for Rochester, New York around 1911 after its purchase by Eastman Kodak.

The city benefited from the economic boom following World War II and was incorporated (with state and county administrations) in 1946.

[5] According to the United States Census Bureau, the city has a total area of 3.70 square miles (9.58 km2), all land.

[6] The 2020 United States census[11] counted 12,895 people, 6,484 households, and 3,514 families in Jennings.

Of all households, 39.8% consisted of individuals and 12.7% had someone living alone who was 65 years of age or older.

There were 6,937 housing units at an average density of 1,874.9 per square mile (723.9/km2).

[14] Jennings has its own Fire Department that protects the city with 16 full-time firefighters.

Jennings FD regularly backs up Northeast Ambulance & Fire Protection District on mutual-aid calls.