The Mardi Gras Indians (also known as Black Masking Indians or Black Maskers) are African American Carnival revelers in New Orleans, Louisiana, known for their elaborate suits and participation in Mardi Gras. The Mardi Gras Indians subculture emerged during the era of slavery from West African, Afro-Caribbean and Native American cultural practices. The Mardi Gras Indians' tradition is considered part of the African diasporan decorative aesthetic, and is an African-American art form.

The Mardi Gras Indian tradition developed as a form of cultural resistance when traditional African religions were banned and Black people could not gather in public or wear masks. Their aesthetic serves as an expression of their culture, religion and spirituality. The tradition of "masking" derives from the West African masquerade ceremony, in which an individual takes on the role of a god or spirit. Some Mardi Gras Indians mask as the Native American allies who shielded their ancestors during slavery; others mask as orisha spirits from the Yoruba religion, or as spirits of the dead, such as the Skull and Bones gangs. Mardi Gras Indians' suits (regalia) and performances provide commentary on social justice issues, political liberation, and transformation. Their ceremonial purposes include healing, protection from the unknown, and communion with the spirits.

Mardi Gras Indians call their krewes "tribes" or "gangs", which should not be confused with Native American tribes. Tribes takes their names from street names, ancestry and important cultural figures. There are more than 40 active tribes, which range in size from half a dozen to several dozen members. Groups are largely independent, but a pair of umbrella organizations loosely coordinates the Uptown Indians and the Downtown Indians. Their suits are displayed in museums in Louisiana and the Smithsonian. The complex designs of these suits are unique to the Mardi Gras Indian artistic community.

In addition to Mardi Gras Day, many of the tribes also parade on Saint Joseph's Day (March 19) and the Sunday nearest to Saint Joseph's Day ("Super Sunday"). Traditionally, these were the only times Mardi Gras Indians were seen in public in full regalia. The New Orleans Jazz & Heritage Festival began the practice of hiring tribes to appear at the Festival as well. In recent years, it has become more common to see Mardi Gras Indians at other festivals and parades in the city. According to Joyce Marie Jackson of Tulane University, the Mardi Gras Indians' fusion of American Indian and West African motifs and music creates "a folk ritual and street theater unique to New Orleans".

Mardi Gras Indians have been practicing their traditions in New Orleans since at least the 18th century. The colony of New Orleans was founded by the French in 1718, on land inhabited by the Chitimacha Tribe, and within the first decade 5,000 enslaved Africans were trafficked to the colony. The West-Central African ethnic groups taken to Louisiana during the transatlantic slave trade were Bambara, Gambian, Akan, Fon, Yoruba, and Kongolese peoples. From 1719 to 1743, almost 30 percent of African people trafficked to New Orleans came from Ouidah, a port in Dahomey on the Bight of Benin. The largest group came from Senegambia. These ethnic groups influenced the culture of Louisiana in food, music, language, religion, and decorative aesthetics. French slaveholders allowed enslaved and free Black people to congregate on Sunday afternoons at Congo Square, where they performed music and religious practices.

New Orleans is known for its Creole heritage, with traditions coming from Native Americans, Africans, and Europeans. A mixed-race population of free people of color contributed to the history and culture of Mardi Gras in the city. The culture of enslaved Africans fused with Afro-Caribbean, Native American and European cultures that syncretized at Congo Square and was practiced during Mardi Gras. The Mardi Gras Indian tradition developed from early encounters between the region's Indigenous (likely Chitimacha) and Black communities. Most of the enslaved people in Louisiana were Black, but 20% of enslaved people were either Native or mixed-race Afro-Indigenous people before abolition.

When enslaved Africans escaped, they encountered Indigenous peoples of Louisiana who shared skills and resources with them. New Orleans was surrounded by swamps, bayous, and rivers where a number of maroon settlements formed. In Louisiana, the Underground Railroad went south to maroon camps because the northern free territories and Canada were too far. These maroon camps attacked whites, stole cattle from nearby farms for food, and freed or absorbed other enslaved people. The maroons lived in huts and grew their own food of corn, squash, rice, and herbs. African culture thrived in maroon communities, and Native Americans often helped them by providing food and weapons to defend themselves from whites and slave catchers.

In colonial Louisiana, there was a settlement known as Natanapalle of armed maroons and Indigenous peoples. In such spaces, freed and escaped Africans adapted some of the culture of Native Americans. Whites in Louisiana feared an alliance of Africans and Indigenous people.