Jan Rys-Rozsévač (1 November 1901 – 27 June 1946) was a Czechoslovakian journalist and politician and leader of fascist organisation Vlajka.

Under this name he published books "Židozednářství - metla lidstva" (Jewish freemasonry - the scourge of humankind, 1938) and "Hilsneriáda a TGM" (Hilsner Affair and Tomáš Garrigue Masaryk, 1939).

Rys-Rozsévač attempted to establish a mass fascist organization and helped to move Vlajka from traditional anti-German chauvinism to collaboration with Nazis and Gestapo.

During 1939 - 1940 Vlajka organized mass meetings against politicians of the First Republic of Czechoslovakia as represented by Masaryk and Beneš.

The German occupational authorities nevertheless decided to support a group of collaborators around Emanuel Moravec, his political competitor.