Louis Guglielmi (3 April 1916 – 4 April 1991) was a Catalan musician of Italian extraction who wrote under the nom de plume Louiguy. 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 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 at Vence.