Kaunas Castle is a medieval castle in Kaunas, the second-largest city in Lithuania. Archeological evidence suggests that it was built during the mid-14th century in the Gothic style. Its site is strategic—a rise on the banks of the Nemunas River near its confluence with the Neris River. About one-third of the castle stood at the beginning of the 21st century.

Kaunas is the second-largest city in Lithuania after Vilnius, the fourth largest city in the Baltic States and an important centre of Lithuanian economic, academic, and cultural life. Kaunas was the largest city and the centre of a county in the Duchy of Trakai of the Grand Duchy of Lithuania and Trakai Palatinate since 1413. In the Russian Empire, it was the capital of the Kaunas Governorate from 1843 to 1915.