The beginnings of Firlej are associated with the Firlej family. The city was founded in 1557 by Mikołaj Firlej. The subsequent owners were Zasławscy, Lubomirscy and Sanguszkowie. In 1839, Firlej took over the property of Henryk Łubieński - the then president of the Bank of Poland.
The city played its part in the November and January uprising. The battles were fought here, as evidenced by the rebels' tombs in nearby Sobolew. Firlej, for the manifestation of patriotism in 1869, lost municipal rights. Serious loss was caused by the First World War - the settlement was destroyed by the retreating Russians. During the occupation, a branch of the AK, Cpt. T. Pośpiecha. The settlement was liberated in July 1944 by the 27th Infantry Infantry Division of the House Army. He reigned after the war
in Firlej, the economic crisis. It was only in the 1960s that the settlement brought economic recovery. His attractive position has been noted.