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.