The USS Iowa was one of four of her class built for the US Navy, planned well before the onset of the war under the assumption the naval treaty would break. As this happened, she was laid down in June 1940 and commissioned in August 1942. Being a "fast battleship", she was intended to outrun the Kongo-class battlecruisers and keep up with carrier groups; she is the fastest battleship ever made. Iowa also gained powerful 16-inch 50-calibre guns over the earlier battleships with 45-calibre guns, along with an incredibly efficient, highly angled armour scheme.

Entering service in early 1943, she had an incredibly long service life, albeit with some time in reserves. She saw service for the rest of WW2, mostly in the form of carrier escort and shore bombardment. This included such famous engagements as Saipan, Guam, and the Battle of the Philippine Sea (nicknamed the Great Marianas Turkey Shoot), where she helped completely decimate the Japanese carrier-based aircraft. The rest of her service in WW2 was more escort and bombardment, including against the Japanese mainland, before the final surrender, which she witnessed in Tokyo Bay. She saw extensive service in the Korean War, doing incredible amounts of damage through bombardment of areas such as Mayang-do, Hŭngnam and Wonsan, using almost 17,000 shells in total during this time.

Mothballed before Vietnam, she returned to service in 1984, this time having Harpoon anti-ship and Tomahawk anti-surface missiles added, and her 20mm and 40mm guns replaced by CIWS systems, even becoming the first battleship equipped with a UAV. She was finally decommissioned for the last time in 1990, later being turned into a museum ship berthed in Los Angeles, where she can still be seen today.

Introduced in Update "Leviathans" in her 1945 refit, USS Iowa is the pinnacle of American battleship design, and captains can expect to lack for nothing from Iowa. Notably, she is the fastest battleship in-game, providing a mobility advantage over even other fast battleships. She also has incredible anti-aircraft firepower, and a lower reload on her main battery compared to the earlier Standard-type battleships found in the US tree. She is also remarkably well protected in both belt and deck armour, and her combination of firepower, protection and speed makes her easily one of, if not the most versatile and powerful battleships in-game. Captains are recommended to take advantage of her superior speed to maintain separation and utilise her exceptional firepower at ranges that most battleships are unable to compete at.