J'ouvert (also spelled as Jouve) and pronounced 'juuvay', is a large street party during Carnival in the eastern Caribbean region. J'ouvert is a contraction of the French jour ouvert, or day open (morning).

J'ouvert is celebrated on many islands, including Anguilla, Antigua & Barbuda, Aruba, Barbados, Dominica, Grenada, Haiti, Jamaica, Saint Lucia, St. Vincent and the Grenadines, St. Kitts and Nevis, Sint Maarten, Trinidad and Tobago, the U.S. Virgin Islands and the British Virgin Islands. It is also a feature of New York City's Labor Day Carnival held in the Crown Heights neighborhood of Brooklyn and Notting Hill Carnival in London, both areas that have a large Caribbean ex-pat communities.

The celebration involves calypso/soca bands and their followers dancing thru the streets. The festival starts well before dawn and peaks a few hours after sunrise. Another part of the tradition involves throwing coloured powders, water, smearing paint, mud, or oil on the participants known as "Jab Jabs".