Yes, Poland used cavalry in World War 2. The Polish cavalry was one of the most famous and effective cavalry forces in the world during the 1930s. It was known for its daring charges and its use of lances. The Polish cavalry was used extensively during the early stages of World War 2, particularly during the Polish September Campaign of 1939. The cavalry was able to achieve some notable successes during this campaign, such as the Battle of Mokra and the Battle of Krasnobród. However, the cavalry was also vulnerable to modern weapons, such as machine guns and tanks. As a result, the Polish cavalry suffered heavy losses during the war and was eventually disbanded in 1944.