4.5 inch (114 mm) gun

4.5 inch gun may refer to:


 * QF 4.5 inch Mk I – V naval gun, a British family of naval guns
 * 4.5 inch Mark 8 naval gun, a contemporary British naval gun
 * BL 4.5 inch Medium Field Gun, a British Army field gun
 * 4.5 inch Gun M1, a United States field gun of World War II era.