The Greek-born singer grew up in Alexandria, Egypt, and arrived in Paris in 1951, where he began to play guitar at nightclubs and met some of the period's best-known singers.
He was introduced to Edith Piaf in the late 1950s and started to write songs for the Parisian star, the most famous of which was "Milord" about a lower-class girl who falls in love with an upper-class British traveler.
Developing a reputation as a singer in his own right in the mid-1960s, the hirsute and heavily bearded Moustaki achieved fame with songs including the immigrant ballad "Le Meteque" and "Ma Liberte", a hymn to the 1960s free-living spirit.
Moustaki, a life-long advocate of left-wing causes, ended his singing career in 2009, later telling newspaper La Croix that he was suffering from an irreversible bronchial illness that made it impossible to carry on.
French Culture Minister Aurelie Filippetti hailed an "artist with convictions who conveyed humanist values... and a great poet", and Twitter was flooded with tributes to a singer who many said had defined their childhoods.
(Reporting By Marine Pennetier and Elizabeth Pineau; Writing Nicholas Vinocur, editing by Paul Casciato)