Katori-class cruisers were originally ordered to serve as training ships in the 1937 and 1939 Supplementary Naval budget.

On 28 July 1940, Katori and her sister ship, Kashima, participated in the last pre-war midshipman cruise, visiting Etajima, Mutsu, Dairen, Port Arthur, and Shanghai.

Vice Admiral Shimizu was wounded in the raid, and Katori sustained enough damage to warrant a return to Yokosuka for repairs.

The ship returned to Kwajalein in May, where on 24 May 1942 the new admiral, of the Sixth Fleet (Submarines) Vice Admiral Marquis Teruhisa Komatsu, ordered Captain Sasaki Hankyu detachment of midget submarines to stage the attack on Sydney Harbour.

Katori returned briefly to Yokosuka in August 1942 for upgrading with two twin Type 96 25 mm AA guns, which were fitted in the forward part of the bridge.

After being under attack by Iowa for about five minutes, Katori sank stern first, with a port side list at 07°45′N 151°20′E / 7.750°N 151.333°E / 7.750; 151.333 about 40 miles (64 km) northwest of Truk.