Five U.S. states have a coastline on the Gulf of Mexico and are known as the Gulf States: Texas, Louisiana, Mississippi, Alabama, and Florida. Their shared shoreline is called the Gulf Coast, sometimes also known as the Gulf South or the South Coast.
Since 2025 the U.S. federal government has officially used the name Gulf of America for the body of water, but the list of states bordering it has not changed. Note that the term “Gulf States” is also used internationally for the Arab states of the Persian Gulf, so context matters.
Source: Gulf Coast of the United States, Wikipedia
Image: Orange Beach, Alabama, by Carol M. Highsmith, public domain, via Wikimedia Commons.