David was born on the 13th of June, 1944, in Newton, Massachusetts, and after graduating from high school, he enlisted in the US Navy the month after his twentieth birthday. He initially deployed to Vietnam early on in the conflict but after five months, David returned to the States in order to receive training on the river patrol boats. When he returned to Vietnam, he displayed actions that would earn him the Medal of Honor. The citation reads:

For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty. As the forward machine gunner on River Patrol Boat (PBR) 124, which was on patrol during the early evening hours, Seaman Ouellet observed suspicious activity near the river bank, alerted his boat captain, and recommended movement of the boat to the area to investigate. While the PBR was making a high-speed run along the river bank, Seaman Ouellet spotted an incoming enemy grenade falling toward the boat. He immediately left the protected position of his gun mount and ran aft for the full length of the speeding boat, shouting to his fellow crewmembers to take cover. Observing the boat captain standing unprotected on the boat, Seaman Ouellet bounded on to the engine compartment cover, and pushed the boat captain down to safety. In the split second that followed the grenade's landing, and in the face of certain death, Seaman Ouellet fearlessly placed himself between the deadly missile and his shipmates, courageously absorbing most of the blast fragments with his body in order to protect his shipmates from injury and death. His extraordinary heroism and his selfless and courageous actions on behalf of his comrades at the expense of his life were in the finest traditions of the U.S. Naval Service.

David’s family received his Medal of Honor on the 30th of January, 1968, from the secretary of the Navy in a ceremony at the Pentagon. Two years later, the USS Ouellet was commissioned in his honor and David George Ouellet is buried in the Woodlawn Cemetery in Wellesley, Massachusetts. His name is also on the Vietnam Veterans Memorial Wall: Panel 16E, Line 30.