In French, the word "Mardi" means "Tuesday," and the word "Gras" means "Fat," meaning that Mardi Gras translates to English as "Fat Tuesday." The name comes from the practice of preparing for the start of a period of fasting on Ash Wednesday, which immediately follows Mardi Gras. Rich foods traditionally associated with this holiday include pancakes, pastries and things like eggs and dairy and other sweet treats which may not be allowed during Lent.

During Mardi Gras, multiple people can carry the title of king because each krewe usually selects a member as king, though some krewes invite a celebrity to serve as the king of their parade. Like other kings, these celebrity kings typically appear in the parade of the krewe that invited them. The Rex Krewe king and queen of Carnival are selected from amongst Louisiana and New Orleans natives who have family connections to the Rex Krewe. The kings tend to be significantly older than queens, a trend that has typically not been updated as other parts of the celebration have modernized.

Mardi Gras is an official public holiday in certain places in the United States and across the globe. It is an official state holiday in Louisiana, and Brazil also has made the Carnival celebration an official public holiday. The holiday tends to be officially recognized only in places that have a strong tradition of celebrating the occasion, including Mobile, Alabama, which hosted the first Mardi Gras parade in the U.S. Louisiana has recognized Mardi Gras as an official public holiday since 1875, when then-Governor Warmoth signed the Mardi Gras Act into law, officially designating the occasion as a state holiday.