PKN Orlen (Polish: Polski Koncern Naftowy Orlen) (WSE: PKN) is a major European oil refiner, and petrol retailer. The company is Poland's and Central Europe's largest publicly traded firm with major operations in Poland, Czech Republic, Germany, and the Baltic States. In 2009, it was ranked in the Fortune Global 500 as the world's 31st largest oil company and the world's 249th largest company overall, and was the only Polish company ranked by Fortune. However, it dropped as low as to the position of 398 by the year 2010.

The firm was created through the merger of Poland's two communist oil monopolies. PKN Orlen has its roots in the creation of C.P.N., Communist Poland's petroleum retail monopoly in 1944. In the 1950s, the second block of PKN Orlen was formed, Petrochemia Płock, a state firm in charge of the refineries in Płock and grew to become the largest complex of its kind in Poland. After the merger of CPN and Petrochemia Plock, the company was renamed into Polski Koncern Naftowy (PKN), with Orlen added several months later as the consortium's brand name. The new name is derived from Orl- for "orzeł" (Polish: eagle) and its adjective "orli", and -en for "energia" (Polish: energy).