Petr Jarchovský (born 6 October 1966 in Prague) 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 Hà Âebejk.
Jarchovský attended high school in Prague and then, from 1987 to 1991, at the Film and TV School of the Academy of Performing Arts in Prague, alongside his high school classmate and future creative collaborator Jan Hà Âebejk. His screenwriting debut was a collaboration with another classmate, Igor Chaun, on a project entitled Very Believable Stories. Around this time, Jarchovský and Hà Âebejk also co-wrote a film based on Hà Âebejk's experiences of socialist summer camps, entitled Let's All Sing A Song, which was later made into a feature film by Ondà Âej Trojan in his directorial debut.
Jarchovský and Hà Âebejk's breakthrough came in 1993 with the film Big Beat, a rock and roll comedy set in the 1950s, written by Jarchovský and Hà Âebejk from a story by Petr à  abach. The film won the Czech Lion award for Best Film in 1993. In 1997 Jarchovský and Hà Âebejk received awards from the Film and Television Association and the Literary Fund for three episodes they had written for the TV series Bachelors, which were awarded for their contribution to dramatic television programming.
The writing and production team behind Big Beat subsequently reunited for two further films, Cosy Dens (; 1999) and Divided We Fall (; 2000), both of which became enormously successful within the Czech Republic. Jarchovský also wrote the screenplay for à ½elary (2003), directed by Ondrej Trojan, which was nominated for the Academy Award for Best Foreign Language Film in 2004.
Jarchovský also teaches at the Department of Screenwriting and Script Editing at FAMU, and works as a script editor for Czech Television.