After a presidential decree earlier in the week, the country's interior department now writes on its website that the large bay will now be called the Gulf of America.
"As a recognition of the gulf's lasting contribution to the USA's economic strength and vitality, President Trump's directive confirms its decisive importance for the nation", the department writes.
In addition to the Mexican Gulf, North America's highest mountain has also changed its name.
The mountain peak in Alaska officially changed its name to Denali in 2015, the name the indigenous people had called it for centuries.
It had then officially been called Mount McKinley since 1917, after the former President William McKinley, who was murdered in 1901. Now the mountain is renamed after him again.
