Petrovice u Karviné is a village in Karviná District, Moravian-Silesian Region, Czech Republic. It has a population of 5,211 (2006), which makes it the second largest village in the Czech Republic (meaning a municipality without an official town status according to Czech laws). 16.2% of the population are the Poles. It lies on the border with Poland, in the historical region of Cieszyn Silesia. The Petrůvka River flows through the village and enters the Olza River in Závada.