Reynaldo Hahn de Echenagucia (9 August 1874 – 28 January 1947) was a Venezuelan-born French composer, conductor, music critic, and singer. He is best known for his songs – mélodies – of which he wrote more than 100.

Hahn was born in Caracas but his family moved to Paris when he was a child, and he lived most of his life there. Following the success of his song "Si mes vers avaient des ailes" (If my verses had wings), written when he was aged 14, he became a prominent member of fin de siècle French society. Among his closest friends were Sarah Bernhardt and Marcel Proust. After the First World War, in which he served in the army, Hahn adapted to new musical and theatrical trends and enjoyed successes with his first opérette, Ciboulette (1923) and a collaboration with Sacha Guitry, the musical comedy Mozart (1926). During the Second World War Hahn, who was of Jewish descent, took refuge in Monaco, returning to Paris in 1945 where he was appointed director of the Opéra. He died in Paris in 1947, aged 72.

Hahn was a prolific composer. His vocal works include secular and sacred pieces, lyric scenes, cantatas, oratorios, operas, comic operas, and operettas. Orchestral works include concertos ballets, tone poems, incidental music for plays and films. He wrote a range of chamber music, and piano works. He sang as well as played his own songs, and made recordings as a soloist and accompanying other performers. After his death his music was neglected but from the late 20th century onward increasing interest has led to frequent performances of many of his works and recordings of all his songs and piano work, much of his orchestral music and some of his stage works.