Ingalls Shipbuilding was a shipyard located in Pascagoula, Mississippi, originally established in 1938, and is now part of Northrop Grumman Ship Systems. It was a leading producer of ships for the US Navy, and at 10,900 employees, the largest private employer in Mississippi.

Ingalls was located where the Pascagoula River runs into the Gulf of Mexico. It started out building commercial ships, but in the 1950s started bidding on Navy work, winning a contract in 1957 to build 12 nuclear-powered attack submarines.

Litton Industries acquired Ingalls in 1961, and in 1968 expanded its facilities to the other side of the river. Ingalls reached a high point of employment in 1977, with 25,000 workers.

Ingalls also produces offshore drilling rigs and cruise ships, and has done naval projects for Egypt, Israel, and Venezuela.

In the 1950s, Ingalls attempted to enter the railroad locomotive business. They catalogued an extensive line, but only one locomotive, known as an Ingalls 4-S, was ever produced. It was sold to the Gulf, Mobile & Ohio Railroad .