Serge Reggiani (born Sergio Reggiani; 2 May 1922 – 23 July 2004) was an Italian-French actor and singer. He was born in Reggio Emilia, Italy, and moved to France with his parents at the age of eight.

After studying acting at the Conservatoire des arts cinématographiques, he was discovered by Jean Cocteau and appeared in the wartime production of Les Parents terribles. He then left Paris to join the French Resistance.

His first feature film was Les portes de la nuit ("Gates of the Night"), released in 1946. He went on to perform in 80 films in total, including Casque d'or, Les Misérables (1958), Tutti a casa, Le Doulos, Il Gattopardo, La terrazza, The Pianist (1998).

Reggiani also triumphed in the theatre in 1959 with his performance in Jean-Paul Sartre's play Les Séquestrés d'Altona. In 1961, Reggiani co-starred with Paul Newman and Sidney Poitier in the film Paris Blues, filmed on location in Paris.

In 1965, at the age of 43, he began a second career as a singer, with the help of Simone Signoret and her husband Yves Montand, and later with the assistance of the French singer Barbara. Reggiani became one of the more acclaimed performers of French chanson, and although he was in his 40s, his rugged image made him popular with both younger and older listeners. His best-known songs include Les loups sont entrés dans Paris ("The Wolves Have Entered Paris") and Sarah (La femme qui est dans mon lit) ("The Woman Who Is in My Bed"), the latter written by Georges Moustaki. He regularly sang songs by Boris Vian (Le Déserteur, Arthur où t'as mis le corps, La Java des bombes atomiques). His young fans identified with his left-wing ideals and anti-militarism, most notably during the student revolts in France in 1968. With age, he became acclaimed as being one of the better interpreters of the chanson and for bringing the poems of Rimbaud, Apollinaire, and Prévert to new audiences.

From 1980, when his son died, Reggiani struggled with alcoholism and depression. In 1995, however, he made a comeback to singing, giving a few concerts despite his deteriorated health and personal distress, the last one being held as late as the spring of 2004.

In later life, he became a painter and gave a number of exhibitions of his works.

Serge Reggiani died in Paris of a heart attack at the age of 82. He is buried in Montparnasse Cemetery.