German composer; youngest surviving son of J. S. Bach. His early music instruction was with his father and, after 1750, with his half-brother Emanuel, who was 21 years his senior. In 1754 he went to Italy, where his teachers included Padre Martini. In Milan he was made cathedral organist in 1760; that year his first opera seria, Artaserse (text by Metastasio), was performed in Turin. It was followed by Catone in Utica (Naples, 1761) and Alessandro nell'Indie (Naples, 1762).

After moving to London, he created pastiches for the King's Theatre late in 1762 and fullscale operas in early 1763. In 1765 he and Carl Friedrich Abel began the Bach-Abel concerts, which helped establish public concerts in London. In 1772 and 1774 he received operatic commissions in Mannheim. He composed Amadis de Gaulefor the Paris Opéra in 1779.

He composed thirteen operas, many sacred vocal works, cantatas, serenatas, songs, nearly fifty symphonies, fifteen symphonies concertantes, some thirty concertos, and much chamber and solo keyboard music.