The Palatine Guard was a military unit of the Vatican. It was formed in 1850 by Pope Pius IX, who ordered that the two militia units of the Papal States be amalgamated. The corps was formed as an infantry unit, and took part in watch-keeping in Rome. The only occasion on which it saw active service was during the token resistance on 20 September 1870 to the occupation of Rome by Italian government troops.

The Papal States, officially the State of the Church, were a conglomeration of territories on the Apennine Peninsula under the direct sovereign rule of the Pope from 756 until 1870. They were among the major states of Italy from the 8th century until the Unification of Italy, between 1859 and 1870.