"Iko Iko" is a much-covered New Orleans song that tells of a parade collision between two "tribes" of Mardi Gras Indians. The lyrics are derived from Indian chants and popular catchphrases. The song, under the original title "Jock-A-Mo", was written in 1954 by James "Sugar Boy" Crawford in New Orleans, but has spread so widely that many people take it to be a much older folk song. The song is closely identified as a Mardi Gras song, but it is equally known as a Top 40 hit. The main melody bears a strong resemblance to the guitar riff in "Son de la Loma" recorded by the Trio Matamoros. "Son de la Loma" was written by Miguel Matamoros sometime before May 8, 1925.

The story tells of a "spy dog" or lookout for one band of Indians encountering the "flag boy" or guidon carrier for another band. He threatens to set the flag on fire.

The lyrics of the song are based on Louisiana Creole French. The phrase Iko Iko may have been derived from one or more of the languages of Gambia, possibly from the phrase Ago!, meaning "listen!" or "attention!". The line from the chorus, Yock-a-mo feen-o and-dan-day echoes the original title amidst Creole palaver.

The song was popularised by The Dixie Cups in 1965. Their version came about by accident. They were in a New York City studio for a recording session when they began an impromptu version of "Iko Iko", accompanied only by drumsticks on a glass ashtray. The tape happened to be running and session producers Leiber and Stoller added bass and drums and released it.

The Dixie Cups, who had heard it sung by their grandmother, knew little about the origin of the song and so the original authorship credit went to the members, Barbara Ann Hawkins, her sister Rosa Lee Hawkins, and their cousin Joan Marie Johnson.

After the Dixie Cups version of the "Iko Iko" was released in 1965, The Dixie Cups and their record label, Redbird Records, were sued by James Crawford, who claimed that "Iko Iko" was the same has his composition "Jockamo". Although The Dixie Cups denied that the two compositions were similar, the lawsuit resulted in a settlement in 1967 with Crawford making no claim to authorship or ownership of "Iko Iko" , but being credited 25% for public performances, such as on radio, of "Iko Iko" in the United States.

In the 1990's, The Dixie Cups became aware that yet another group of people were claiming authorship of "Iko Iko"—their ex-manager Joe Jones and his family filed a copyright registration in 1991, alleging that they wrote the song in 1963. Joe Jones successfully licensed "Iko Iko" outside of North America, including for the soundtrack of Mission Impossible 2 in 2000. The Dixie Cups filed a lawsuit against Joe Jones, and there was eventually a jury trial in New Orleans, where they were represented by well known music attorney Oren Warshavsky in front of Senior Federal Judge Peter Beer. The jury returned a unanimous verdict on March 6, 2002, affirming that The Dixie Cups were the only writers of "Iko Iko" and granting them more money than they were seeking. The Fifth Circuit Court of Appeals upheld the jury verdict and sanctioned Joe Jones.

The song is regularly performed by various artists from New Orleans such as the Neville Brothers (who have recorded it in a medley with the melodically-related Mardi Gras song "Brother John" as "Brother John/Iko Iko"), Larry Williams, Dr. John, The Radiators, Willy DeVille, Buckwheat Zydeco and Zachary Richard, and can often be heard on the streets and in the bars of New Orleans, especially during Mardi Gras.

It has also been covered by Cyndi Lauper, the Grateful Dead, Cowboy Mouth, Warren Zevon, Long John Baldry, Dave Matthews & Friends, Indigo Girls, The Ordinary Boys, Glass Candy, and Sharon, Lois & Bram among others. Aaron Carter covered the song for The Little Vampire soundtrack, and The Belle Stars' cover was featured in the film Rain Man. A later version by Zap Mama, with rewritten lyrics, was featured in the opening sequences of the film Mission: Impossible II. Eurodance act Captain Jack re-popularized the tune in Germany in 2001.

The song proved most successful on the UK charts by singer Natasha England who took it into the top 10 in 1982. Her version, released the same week as The Belle Stars, charted higher and significantly outsold their rival version. This highly infectious recording featured the production talents of Tom Newman ("Tubular Bells"), and featured Mel Collins on sax, Graham Broad on drums and Brad Lang on bass.