Sylvius Leopold Weiss (12 October 1687 – 16 October 1750) was a German composer and lutenist. Born in Grottkau near Breslau, the son of Johann Jacob Weiss, also a lutenist, he served at courts in Breslau, Rome, and Dresden, where he died. Until recently, he was thought to have been born in 1686, but recent evidence suggests that he was in fact born the following year. In later life, Weiss became a friend of Wilhelm Friedemann Bach and met J.S. Bach through him. Bach and Weiss were said to have competed in improvisation, as the following account by Johann Friedrich Reichardt describes: