The Battle of the Ice, also known as the Battle of Lake Peipus, is a battle between the Republic of Novgorod and the Livonian branch of the Teutonic Knights (whose army consists mostly of Estonians) on April 5, 1242, at Lake Peipus.

The battle is notable for having been fought largely on the frozen lake.The battle is a significant defeat sustained by Roman Catholic crusaders during the Northern Crusades, which are directed against pagans and Eastern Orthodox Christians rather than Muslims in the Holy Land.

The crusaders' defeat in the battle marks the end of their campaigns against the Orthodox Novgorod Republic and other Russian territories for the next century.