The Type 10 or 12 cm/45 10th Year Type naval gun was a Japanese 120 mm calibre dual purpose anti-aircraft and coastal defense gun used during the Second World War. It was derived from the 12 cm/45 3rd Year Type naval gun. The Type 10 number was designated for the year the gun was accepted, the 10th year of Emperor Taishō's reign, 1921 in the Gregorian calendar.