The 551st Strategic Missile Squadron is an inactive United States Air Force unit that had seven campaigns from 1943-1945.
The squadron assembled at its combat station, RAF Great Ashfield, England, and began participating in the strategic bombing campaign against Germany, flying its first combat mission on 17 July 1943. On 17 August 1943, the squadron participated in an attack on the Messerschmitt aircraft factory at Regensburg, which involved a long flight over heavily defended enemy territory with little protection from escorting fighters. On 12 May 1944, the squadron flew with the 385th Group as it led the 4th Combat Bombardment Wing through heavy opposition to attack an airplane repair facility at Zwickau. It struck coastal defenses in June 1944 in preparation for Operation Overlord, the Normandy invasion, and on D-Day attacked transportation chokepoints and marshalling yards. In late July, it attacked enemy positions to support Operation Cobra, the breakout at Saint Lo. In late December 1944 and early January 1945, it carried out attacks on German fortifications and transportation to support forces engaged in the Battle of the Bulge. The squadron flew its last mission on 20 April 1945. 
