Up to 3,500 people attended the gathering on the Normandy coast, police said.
About 2,000 of them were scouts, mainly from the United States and Europe.
Organised by the Transatlantic Council Boy Scouts of America and Normandy body Planete Bleue... SOS the ceremony included the projection of archived images on two huge screens, accompanied by music from the University Choir of
Three French jets flew over Omaha Beach and the fast patrol boat, the Broadsword, of the Cherbourg maritime police made a sweep in front of the crowds to commemorate the "many young Americans who sacrificed their lives", in the organisers's words.
The gathering was the seventh organised by the Transatlantic Council Boys Scouts of America in Lower Normandy since 1994.