Subsequent smashes including 1969's "Wight Is Wight" (a celebration of the Isle of Wight rock festival) and "Paul Chantait Yesterday" (a tribute to the Beatles) followed, and in 1971 Delpech and Vincent teamed for the signature hit of the singer's career, the classic "Pour un Flirt." Delpech opened 1972 with a three-week headlining stint at L'Olympia, and while he continued his collaboration with Vincent, he also partnered with writers including Jean-Michel Rivat, Pierre Papadiamandis, and Michel Pelay, reeling off a string of blockbusters including "Les Divorcés," "Que Marianne Était Jolie," "Le Chasseur," and "Quand J'étais Chanteur." However, in 1975 Delpech divorced his wife, Chantal, and while the subsequent "Le Loir-et-Cher" proved another enormous hit, he soon entered a period of intense clinical depression that effectively crippled his creative momentum. After seeking refuge in Buddhism, he later turned to Catholicism, and even explored his search for personal and spiritual meaning in a profoundly introspective memoir, L'Homme Qui Avait Bâti Sa Vie Sur le Sable. Delpech recorded and performed rarely during this period, and after issuing the 1977 LP 5000 km he virtually disappeared from the French pop landscape. Finally, he resurfaced in 1983 with the single "Animaux, Animaux," that same year falling in love with painter Geneviève Garnier-Fabre, who became his wife two years later. Their romance seemed to reignite Delpech's passion for making music, and in 1985 he issued Loin d'Ici, his first new LP in close to a decade.

While Delpech never recaptured the commercial esteem he enjoyed during the better part of the 1970s, he retained a devoted audience and never rested on past laurels. For 1989's J'étais un Ange, he teamed with composer Dider Barbelivien, and three years later reunited with Vincent for Les Voix du Brésil, which updated their signature sound with influences drawn from across the breadth of world music. Delpech celebrated the record's release with a string of dates at L'Olympia, his first appearances at the legendary venue in two decades. He nevertheless retreated from performing for five years, finally returning in mid-1997 with a self-titled LP that summarized his outlook on life and art as he entered his fifties. Despite its autumnal themes, the record's contemporary pop sensibilities found favor with critics and audiences alike, and in September he headlined a weeklong stay at the Casino de Paris. Delpech's return to the limelight again proved brief, however, and he spent the remainder of the decade collaborating with wife Geneviève on a novel, De Cendres et de Braises, published in 2000. Late that same year he issued the retrospective J'étais un Ange, celebrating its release with a brief French tour highlighted by guest appearances by the likes of Alain Chamfort, Marc Lavoine, and Claude Nougaro. Finally, in 2004 Delpech released the roots music-inspired Comme Vous, his first new LP in seven years. Two years later, he launched &, a collection of perennial fan favorites re-recorded as duets alongside Alain Souchon, Bénabar, and others. In 2009 he released another new album, Sexa, which recontextualized and updated his classic smooth sound, and was warmly received. After that he took a break from music for a few years to focus on acting, appearing in the 2011 romantic musical drama film Les Bien-Aimés, and the mockumentary L'Air de Rien, in which he played a fictionalized version of himself.