Jakub Šimon Jan Ryba (October 26, 1765 – April 8, 1815) was a Czech teacher and composer of classical music. His most famous work is Czech Christmas Mass "Hey, Master!" (Česká mše vánoční "Hej mistře!"). Ryba was born in Přeštice near Plzeň. His father was a schoolteacher, which was a very poorly paid occupation at the time. In 1780 Ryba went to Prague, where he studied at the Piarist gymnasium. His teacher Cassianus Hanel taught him music.