A krewe (pronounced in the same way as "crew") is an organization that puts on a parade and or a ball for the Carnival season. The term is best known for its association with New Orleans Mardi Gras, but is also used in other Carnival celebrations around the Gulf of Mexico, such as the Gasparilla Pirate Festival in Tampa, Florida, and Springtime Tallahassee as well as in La Crosse, Wisconsin and at the Saint Paul Winter Carnival.

The word is thought to have been coined in the early 19th century by an organization calling themselves Ye Mistick Krewe of Comus, as an archaic affectation; with time it became the most common term for a New Orleans Carnival organization. The Mystick Krewe of Comus itself was inspired by a Mobile mystic society, with annual parades in Mobile, Alabama, called the Cowbellion de Rakin Society that dated from 1830.

Krewe members are assessed fees in order to pay for the parade and/or ball. Fees can range from thousands of dollars a year per person for the most elaborate parades to as little as $20 a year for smaller marching clubs. Criteria for krewe membership varies similarly, ranging from exclusive organizations largely limited to relatives of previous members to other organizations open to anyone able to pay the membership fee. Krewes with low membership fees may also require members to work to help build and decorate the parade floats and make their own costumes; higher priced krewes hire professionals to do this work. Parading krewe members are usually responsible for buying their own throws, the trinkets thrown to parade spectators according to Mobile and New Orleans tradition.