The Pennsylvania class consisted of two super-dreadnought battleships built for the United States Navy just before the First World War. Named Pennsylvania and Arizona, after the American states of the same names, the two battleships were the United States' second battleship design to adhere to the "all or nothing" armor scheme. They were the newest American capital ships when the United States entered the First World War.

The Nevada-class battleships represented a marked increase in the United States' dreadnought technology, and the Pennsylvania class was intended to continue this with slight increases in the ships' capabilities, including two additional 14-inch (356 mm)/45 caliber guns and improved underwater protection. The class was the second standard type battleship class to join the US Navy, along with the preceding Nevada and the succeeding New Mexico, Tennessee and Colorado classes.