The XII (1st Royal Saxon) Army Corps / XII AK () was a Saxon corps level command of the Saxon and German Armies before and during World War I. The Corps was formed as the Royal Saxon Corps on 1 April 1867 and headquartered in Dresden. Initially, it commanded the 1st Royal Saxon Infantry Division in Dresden and the 2nd Royal Saxon Infantry Division in Leipzig. After the XIX (2nd Royal Saxon) Corps was set up on 1 April 1899 as the headquarters for the western part of the Kingdom of Saxony, XII Corps was made responsible for the eastern part of the Kingdom.