The Regina Maria Pia class was a group of four ironclad warships built for the Italian Regia Marina (Royal Navy) in the 1860s.

Regina Maria Pia, San Martino, and Ancona were discarded in 1903–1904, and Castelfidardo joined them in the breaker's yard in 1910.

Italy considered the Austrian Empire to be its main rival, since it controlled predominantly Italian areas, including Venice.

In 1862, the four ships of the Regina Maria Pia class were ordered from French shipyards, under the direction of Vice Admiral Carlo Pellion di Persano, then the Italian Navy Minister.

They were protected by iron belt armor that was 4.75 inches (121 mm) thick and extended for the entire length of the hull at the waterline.

Each ship had a capacity of 485 long tons (493 t) of coal, which allowed them to steam for 2,600 nautical miles (4,800 km; 3,000 mi) at a speed of 10 knots (19 km/h; 12 mph).

[2][3] All four ships of the class entered service in time to see action during the Third Italian War of Independence against the Austrian Navy in 1866.

Persano, now the commander of the Italian fleet, adopted a cautious strategy and conducted only one major offensive operation, which was directed at the island of Lissa.

Regina Maria Pia, Ancona, and San Martino were stricken from the naval register in 1903–1904, while Castelfidardo lingered on as a torpedo training ship until 1910, when she too was sold for scrapping.