Johann Ernst Bach

Johann Ernst Bach (baptised ; died 21 March 1739) (also known as Johannes Ernestus Bach) was a German organist in the Bach family. He was born in Arnstadt as the third child of Johann Christoph Bach senior – twin brother of Johann Sebastian Bach's father, Johann Ambrosius Bach.

After his father's death, he grew up with relatives in Ohrdruf, where attended the Lyzeum together with his cousin Johann Sebastian. From April 1701, he lived in Hamburg for half a year, to study the organ. In 1728, he also became organist of the Oberkirche and the Liebfrauenkirche.

An application for the post of organist in Gehren in 1727 was not successful.

Nothing is known of any compositions of his own. It is possible, however, that he was the previous owner of the Altbachisches Archiv (Old Bach's archive).