The 766th Bombardment Squadron was activated at Wendover Field, Utah on 1 July 1943 as one of the four original squadrons assigned to the 461st Bombardment Group.
 After training with Consolidated B-24 Liberators under the Second and Fourth Air Forces in the United States, the squadron departed for the Mediterranean Theater of Operations on New Year's Day of 1944.

The squadron arrived at its combat station, Torretto Airfield, Italy by the end of February 1944.
 The air echelon ferried its Liberators to Italy via the Southern Ferry Route, pausing for additional training in North Africa before joining the ground echelon in Italy.
 The squadron flew its first combat mission in April 1944.

The squadron was engaged primarily in the strategic bombing campaign against Germany, attacking communications, industrial facilities and other enemy strategic targets in Austria, Czechoslovakia, France, Germany, Greece, Italy, Romania and Yugoslavia.
 It participated in the campaign against Axis petroleum production with attacks against facilities at Brux Czechoslovakia; Blechhammer, Germany; and Moosbierbaum and Vienna in Austria.
 It received a Distinguished Unit Citation (DUC) for an attack on petroleum facilities at Ploesti, Romania on 15 July 1944, when it heavily damaged its objective, despite clouds and smoke obscuring the target and opposition by flak and interceptors.

it also conducted strategic attacks against enemy airfields and aircraft manufacturing centers.
 On one of its early missions, it attacked an aircraft component manufacturing facility at Budapest, Hungary, battling its way through enemy air defenses.
 This attack earned the squadron its first DUC.

The squadron was occasionally diverted from its strategic mission, flying air support and air interdiction missions.
 During Operation Dragoon, the invasion of southern France in August 1944, it hit artillery positions.
 The following month it flew airlift missions, transporting supplies to forces in France.
 Some of its last missions were flown to support Operation Grapeshot, the spring 1945 offensive in northern Italy.

Following V-E Day, the squadron flew supplies to prisoners of war in Austria.
 It began returning to the United States in early July.
It reassembled at Sioux Falls Army Air Field, South Dakota at the end of the month and was inactivated there on 28 August 1945.
The 766th Bombardment Squadron was activated at Wendover Field, Utah on 1 July 1943 as one of the four original squadrons assigned to the 461st Bombardment Group.  After training with Consolidated B-24 Liberators under the Second and Fourth Air Forces in the United States, the squadron departed for the Mediterranean Theater of Operations on New Year's Day of 1944.
The squadron arrived at its combat station, Torretto Airfield, Italy by the end of February 1944.  The air echelon ferried its Liberators to Italy via the Southern Ferry Route, pausing for additional training in North Africa before joining the ground echelon in Italy.  The squadron flew its first combat mission in April 1944.
The squadron was engaged primarily in the strategic bombing campaign against Germany, attacking communications, industrial facilities and other enemy strategic targets in Austria, Czechoslovakia, France, Germany, Greece, Italy, Romania and Yugoslavia.  It participated in the campaign against Axis petroleum production with attacks against facilities at Brux Czechoslovakia; Blechhammer, Germany; and Moosbierbaum and Vienna in Austria.  It received a Distinguished Unit Citation (DUC) for an attack on petroleum facilities at Ploesti, Romania on 15 July 1944, when it heavily damaged its objective, despite clouds and smoke obscuring the target and opposition by flak and interceptors.
it also conducted strategic attacks against enemy airfields and aircraft manufacturing centers.  On one of its early missions, it attacked an aircraft component manufacturing facility at Budapest, Hungary, battling its way through enemy air defenses.  This attack earned the squadron its first DUC.
The squadron was occasionally diverted from its strategic mission, flying air support and air interdiction missions.  During Operation Dragoon, the invasion of southern France in August 1944, it hit artillery positions.  The following month it flew airlift missions, transporting supplies to forces in France.  Some of its last missions were flown to support Operation Grapeshot, the spring 1945 offensive in northern Italy.
Following V-E Day, the squadron flew supplies to prisoners of war in Austria.  It began returning to the United States in early July. It reassembled at Sioux Falls Army Air Field, South Dakota at the end of the month and was inactivated there on 28 August 1945.
766th Bombardment Squadron