Johann Gottfried Bernhard Bach (May 11, 1715 – May 27, 1739) was the fourth child of Johann Sebastian Bach and Maria Barbara Bach to reach adulthood.
He was born in Weimar. In 1723 his father was appointed Thomaskantor in Leipzig. J.S. Bach is believed to have moved to Leipzig partly because of the educational opportunities there for his children. J.G.B. Bach attended the Thomasschule, where his father was responsible for the musical education, and also studied privately with his father. In contrast to his elder brothers Wilhelm Friedemann and Carl Philipp Emanuel he did not get the opportunity to study at Leipzig University after finishing school. Instead, he competed for a post as musician.
Johann Gottfried Bernhard first served as organist at the Marienkirche in Mühlhausen in 1735 and, after leaving the town charged with debts, managed with the support of his father to find a new engagement as organist at the Jakobikirche in Sangerhausen.
In 1738, he secretly abandoned a career in music in order to study law in Jena. There he died prematurely at aged 24. It is unknown if, like his brothers, Gottfried Bernhard was a composer.