Polish 3rd Legions Infantry Division (3. Dywizja Piechoty Legionów) was a tactical unit of the Polish Army between the World Wars. Formed in 1919, as a third unit composed significantly of veterans of the Polish Legions in World War I (after Polish 1st Legions Infantry Division and Polish 2nd Legions Infantry Division), it saw extensive action during the Polish-Bolshevik War and the Invasion of Poland. In the interbellum period, the headquarters of the division was stationed in Zamość, while its regiments were garrisoned in Chelm, Lublin, Zamosc and other locations.
The division was officially formed on April 9, 1919, in former Austrian Galicia, during the ongoing Polish-Ukrainian War. At the beginning it consisted of three regiments (7th Legions Infantry, 8th Legions Infantry and 3rd Legions Light Artillery), but was later reinforced with 9th Infantry Regiment.