Aoba (Aoba class of heavy cruisers) was 607.5 feet in length, with a beam of 52 feet, and draft of 18.75 feet, and was capable of 35.5 knots.Propulsion was by 12 Kampon boilers driving four sets of Brown Curtiss geared turbine engines, with four shafts turning three-bladed propellers. The ship was armored with a 76 mm side belt, and 36 mm  armored deck.

Aoba’s main battery was six 20 cm/50 3rd Year Type naval guns, mounted in three twin turrets, two forward and one aft. Her secondary armament included four 12.7 cm/40 Type 45 naval guns in four single mounts on each side, and 8 torpedoes in two quad launchers. Aoba was also equipped with an aircraft catapult.