Bolzano was a unique heavy cruiser, sometimes considered to be a member of the Trento class, built for the Italian Regia Marina in the early 1930s, the last vessel of the type to be built by Italy. A modified version of the earlier Trento class, she had a heavier displacement, slightly shorter length, a newer model of 203 mm (8 in) gun, and a more powerful propulsion system, among other differences influenced by the Zara class that had followed the Trentos. Bolzano was built by the Gio. Ansaldo & C. between her keel laying in June 1930 and her commissioning in August 1933.

A heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 inches) in calibre, whose design parameters were dictated by the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930. Heavy cruisers were generally larger, more heavily-armed and more heavily-armoured than light cruisers while being smaller, faster, and more lightly-armed and armoured than battlecruisers and battleships. Heavy cruisers were assigned a variety of roles ranging from commerce raiding to serving as 'cruiser-killers,' i.e. hunting and destroying similarly-sized ships