Born in France to an Egyptian father and a Franco-American mother, Khalil Chahine began his career as a guitarist, accompanying numerous artists from diverse backgrounds, including Michel Legrand, Martial Solal, Jacques Dutronc, Diane Dufresne, and Henri Salvador.

He notably took part in the band formed by Jacques Dutronc to accompany him at the Casino de Paris in November 1992. A CD was recorded and produced on this occasion by Dominique Blanc-Francard, Jacques Dutronc au Casino, featuring performances by Jannick Top, André Ceccarelli, and Bernard Arcadio. A live recording was also captured by Jean-Marie Périer.

He then continued his career primarily as a composer and arranger.

He composes music for television (jingles for the news and weather on France 2 in the mid-1990s) and for film (Vénus Beauté (Institut), 1999; Monsieur Batignole, 2000).

In 2012, the Louvre Museum invited Khalil Chahine to compose an original score for the first animated film, Les Aventures du prince Ahmed, created in 1926 by Lotte Reiniger. The music, written for electronics and an instrumental ensemble, was performed during screenings, notably on the stage of the Louvre Auditorium in 2012, at the Théâtre Liberté in Toulon for the Musiques pour l’écran festival in 2014, and at the Jazz & Garonne festival in Marmande in 2015.

In 2018, his 8th album, Kafé Groppi, was released as a tribute to the Groppi Café in Cairo.