Pierre-Jean Garat (25 April 1764 – 1 March 1823) was a French singer and nephew of Dominique Joseph Garat. He was born in Ustaritz. Garat devoted himself from an early age to the cultivation of his musical talents. Because he professed a distaste for the legal profession, which his father wished him to pursue, he was deprived of his allowance, but through the patronage of a friend he obtained the office of secretary to Comte d'Artois, and was afterwards engaged to give musical lessons to the queen of France. At the beginning of the Revolution he accompanied Rode to England, where the two musicians appeared together in concerts. He returned to Paris in 1794. After the Revolution he became a professional singer and was thrown into prison for a song he composed about the misfortunes of the royal family.
On regaining his liberty Garat went to Hamburg, where he at once achieved extraordinary success. By his subsequent appearances in Paris, and his visits to Italy, Spain, Germany and Russia, he made for himself a reputation as a singer unequalled by any other of his own time. In addition, he became a professor of singing for the Conservatoire de Musique, and composed several songs. He was known as a keen partisan of Gluck in opposition to Handel.