William David Halyburton Jr. (October 2, 1924 – May 10, 1945) was a United States Navy hospital corpsman who was killed in action during World War II while assigned to a Marine Corps rifle company.

He was posthumously awarded the nation's highest military decoration for valor, the Medal of Honor, for heroic actions "above and beyond the call of duty" on May 10, 1945, during the Battle of Okinawa.

Moving steadily forward despite the enemy's merciless barrage, he reached the wounded marine who lay farthest away and was rendering first aid when his patient was struck for the second time by a Japanese bullet.

Instantly placing himself in the direct line of fire, he shielded the fallen fighter with his own body and staunchly continued his ministrations although constantly menaced by the slashing fury of shrapnel and bullets falling on all sides.

Alert, determined and completely unselfish in his concern for the helpless marine, he persevered in his efforts until he himself sustained mortal wounds and collapsed, heroically sacrificing himself that his comrade might live.