David Kellner (1670 – April 6, 1748) was a German Baroque composer and a contemporary of Bach.
Kellner was born in Liebertwolkwitz near Leipzig in the Electorate of Saxony. In addition to compositions for the lute, which are highly regarded today, he wrote about music theory and, in particular, about composing for equal temperament. His diagram of the circle of fifths is the earliest surviving example of the modern representation of major and minor keys in two concentric circles, with the major key immediately outside its corresponding minor key.