After receiving his training at the Conservatoire national supérieur d'art dramatique (National Conservatory of Dramatic Arts of Paris) in the classes of Jean Yonnel and Georges Le Roy, Yves Gasc joined the Comédie-Française in 1978 and became a sociétaire in 1982. Subsequent to his leaving the Troupe in December 1997, he was appointed as a sociétaire honoraire in January 1998.
From 1953 to 1963, he enrolled in the Théâtre National Populaire (T.N.P) in Villeurbanne, where he got the chance to play de Musset, Shakespeare, Büchner, Beaumarchais, Brecht, Molière and Pirandello. Jean Vilar put him in charge of the Théâtre national de Chaillot’s poetic and literature mornings and evenings at the Festival of Avignon and on tour. Furthermore, he put on stage plays by Corneille, Labiche, Valéry, Hugo, Pinget, and very often collaborated with Laurent Terzieff.
Between 1973 and 1977, he enrolled in the Renaud-Barrault Company, where he got the chance to play Claudel, Higgins’ Harold and Maud, Villiers-de-l'Isle-Adam, Duras.

At the Comédie-Française, he felt equally at home playing from both the classic and contemporary repertoire, notably in Samuel Beckett’s_Happy Days_, in Molière’s Don Juan, in Chekhov’s The Three Sisters, in Giraudoux’s The Madwoman of Chaillot, in Euripides’s Medea, and in Hugo’s Mary Tudor. And the list goes on to include Molière’s The School For Wives, and Marivaux’s The Second Surprise of Love, Genet’s The Balcony, Molière’s The Bourgeois Gentleman. He also performed in Bernanos’ Dialogues of the Carmelites, in Svevo’s A Husband, in Sophocles’ Antigone, in Camus’ Caligula, in Balzac’s Le Faiseur, in Feydeau’s Occupe-toi d'Amélie, in Labiche’s Moi, in Ionesco’s Jack, or The Submission, in Molière’s Les Femmes savantes, in Grumberg’s Amorphe d'Ottenburg, in Corneille’s Cinna, in Gombrowicz’s The Marriage and in Magnin’s Soap Opera.
At the Comédie-Française, he staged Andrée Chedid’s Le Montreur, Robert Pinget’s Paralchimie, Eduardo Manet’s Le jour où Mary Shelley rencontra Charlotte Brontë, Marivaux’s The Triumph of Love, Jules Renard’s Le Pain de ménage and Le Plaisir de rompre, Alain-René Lesage's Turcaret, David Mamet’s The Shawl, Jean-Claude Brisville's L'Entretien de M. Descartes avec M. Pascal le jeune and Le Fauteuil à bascule.


In the movies, he played under the direction of Marguerite Duras, Pierre Lary, Bertrand Blier, Alain Corneau and on television, he worked with Marcel Bluwal, Michel Favart, Claude Santelli and Josée Dayan.