Petr Zelenka (born 21 August 1967 in Prague, Czechoslovakia) is a Czech playwright and director of theatre and film. His films have been recognized at international festivals in Moscow and Rotterdam. In 2008, his film Karamazovi was the Czech Republic's official Oscar submission for Best Foreign Language Film.

An early notable work is a black comedy, Tales of Common Insanity (2004) (Czech: Příběhy obyčejného šílenství), which he directed at Dejvické divadlo. He received the Alfréd Radok Award for Best Play. The play was later staged in other Czech theatres as well as in Poland, Hungary, Slovakia, Slovenia and Germany. It was also published in English and translated to Russian. For his film Mnâga – Happy End he won the 1996 Findling Award at the Filmfestival Cottbus.

In 2005, Zelenka adapted the comedy as a film, released as Wrong Side Up, which won two movie festival awards in 2006 and was nominated for six other awards. His second most notable play is Teremin, inspired by the life of Russian inventor Léon Theremin.

His 2008 film, Karamazovi, was the Czech Republic's official Oscar submission for Best Foreign Language Film. His 2010 election advertisement "Přemluv bábu a dědu" caused controversy as critics believed it was offensive against elder people[1] and "an imperfect copy of Sarah Silverman's stand-up video."