The Gulf Coast of the United States, sometimes referred to as the Gulf South,^{[citation needed]}South Coast, or 3rd Coast, comprises the coasts of American states that are on the Gulf of Mexico, which includes Texas, Louisiana, Mississippi, Alabama, and Florida and are known as the Gulf States. All Gulf States are located in the Southern region of the United States.

The economy of the Gulf Coast region is dominated by industries related to fishing, aerospace, agriculture, and tourism. The region is anchored^{[citation needed]} by the cities of Corpus Christi, Houston, Baton Rouge, New Orleans, Mobile, Pensacola, Tampa, and increasingly, Sarasota, all the centers of their respective metropolitan areas and containing large ports.

The Gulf Coast is made of many inlets, bays, and lagoons. The coast is also intersected by numerous rivers, the largest of which is the Mississippi River. Much of the land along the Gulf Coast is, or was, marshland. Ringing the Gulf Coast is the Gulf Coastal Plain which reaches from Southern Texas to the western Florida Panhandle.while the western portions of the Gulf Coast are made up of many barrier islands and peninsulas, including the 130 miles (210 km) Padre Island and Galveston Island located in the U.S. State of Texas. These landforms protect numerous bays and inlets providing as a barrier to oncoming waves. The central part of the Gulf Coast, from eastern Texas through Louisiana, consists primarily of marshland. The eastern part of the Gulf Coast, predominantly Florida, is dotted with many bays and inlets.