Cognomen Petlak (Petlak 
) , around the world, is a rare family name. The cognomen Petlak is habitual in Czechia, where it is quite a rare surname, Slovakia, and Bahrain, where it is a rare surname. Measured by absolute frequency, this name is the most popular in Czechia, Poland, and the United States. Also, Petlak is the forename as well as the last name.