Louis Guglielmi (3 April 1916 – 4 April 1991), known by his pen name Louiguy (French pronunciation: ​[lwi.ɡi]), was a Spanish-born French musician of Italian descent. He wrote the melody for Édith Piaf's lyrics of "La Vie en Rose" and the Latin jazz composition "Cerisier rose et pommier blanc", a popular song written in 1950, made famous in English as "Cherry Pink (and Apple Blossom White)", which was recast as a resounding mambo hit for Pérez Prado.

Guglielmi was born in Barcelona. He studied music at the Conservatoire de Paris in the same class as Maurice Baquet, Henri Betti, Paul Bonneau and Henri Dutilleux. He created almost three dozen film scores, beginning in 1946 with La Rose de la mer and including Mourir d'aimer (1970; in English To Die of Love). Among the last was the score for Jean Gabin's final gangster flick, Verdict (1974). He died in Vence, one day after his 75th birthday.