Bach married his second cousin Maria Barbara Bach in 1707. They had seven children, four of whom survived to adulthood:

• Catharina Dorothea (28 December 1708 – 14 January 1774).
• Wilhelm Friedemann (22 November 1710 – 1 July 1784).
• Carl Philipp Emanuel (8 March 1714 – 14 December 1788).
• Johann Gottfried Bernhard (11 May 1715 – 27 May 1739).

Maria died in 1720, and Bach married Anna Magdalena Wilcke in 1721. They had a further 13 children, six of whom survived to adulthood:

• Gottfried Heinrich (1724–63)
• Elisabeth Juliana Friederica, called "Lieschen" (1726–81)
• Johann Christoph Friedrich, the "Bückeburg" Bach (1732–95)
• Johann Christian, the "London" Bach (1735–82)
• Johanna Carolina (1737–81)
• Regina Susanna (1742–1809)

Although Bach fathered 20 children, only 10 survived infancy. He has no known descendants living today. His great-granddaughter—Frau Carolina Augusta Wilhelmine Ritter, who died 13 May 1871—was his last known descendant.^[39]