He was awarded the medal for heroic actions "above and beyond the call of duty" on March 27, 1953, while assigned to a Marine Corps rifle company during the Korean War.

[2] Charette enlisted in the U.S. Navy on January 11, 1951, during the Korean War (1950–1953) and underwent recruit training at Naval Station Great Lakes, Illinois.

[4] Charette and the other Fox Company corpsmen faced a growing number of casualties exposed to hostile small arms and mortar fire when Marines from his rifle company joined in the counterattack on March 27 against "Vegas Hill" with Charette's Third Platoon Commander, 2nd Lieutenant Theodore H. Chenoweth (Navy Cross), leading the assault in hand-to-hand fighting up the south side of the hill.

[2] While still serving in Korea after the fighting ended there, he learned that he would receive the United States' highest military decoration for valor, the Medal of Honor.

In 1958, aboard the USS Canberra, he had the honor of selecting the World War II remains (one from the Pacific, and one from the European) that would be placed in the Tomb of the Unknowns in Arlington National Cemetery.

Charette's military decorations and awards include:[3] The President of the United States in the name of The Congress takes pleasure in presenting the MEDAL OF HONOR to for service as set forth in the following

For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty in action against enemy aggressor forces during the early morning hours of 27 March 1953.

Participating in a fierce encounter with a cleverly concealed and well-entrenched enemy force occupying positions on a vital and bitterly contested outpost far in advance of the main line of resistance, HM3 Charette repeatedly and unhesitatingly moved about through a murderous barrage of hostile small-arms and mortar fire to render assistance to his wounded comrades.

When an enemy grenade landed within a few feet of a marine he was attending, he immediately threw himself upon the stricken man and absorbed the entire concussion of the deadly missile with his body.

Although sustaining painful facial wounds, and undergoing shock from the intensity of the blast which ripped the helmet and medical aid kit from his person, HM3 Charette resourcefully improvised emergency bandages by tearing off part of his clothing, and gallantly continued to administer medical aid to the wounded in his own unit and to those in adjacent platoon areas as well.

CHARETTE stood upright in the trench line and exposed himself to a deadly hail of enemy fire in order to lend more effective aid to the victim and to alleviate his anguish while being removed to a position of safety.

A Sea Cadet unit is named in his honor, National Naval Medical Center Bethesda William R. Charette Battalion.