Petr Jarchovský is a Czech screenwriter, whose writing credits include Big Beat (1993), Cosy Dens (1999), and Divided We Fall (2000). Jarchovský is a frequent and long-term collaborator with director Jan Hřebejk.

Cosy Dens is a 1999 Czech film directed by Jan Hřebejk. It is loosely based on the novel Hovno Hoří by Petr Šabach. It was voted the best Czech film by Reflex magazine in 2011.