David McCoy was a male Human in the 23rd century. He was the father of Doctor Leonard McCoy, chief medical officer of the USS Enterprise and grandfather of Joanna McCoy. (Star Trek III: The Search for Spock)
David, like previous generations of McCoys, passed down the family recipe for Southern baked beans to his son, Leonard. Years later, Leonard would reveal that the "secret ingredient" was Tennessee whiskey.
Late in his life, David was stricken with an incurable painful disease and begged his son to help him end his life. A cure was discovered soon after, subsequently causing Leonard many years of regret from causing his father's apparently needless death.
In the Star Trek V: The Final Frontier novelization, his full name is given as David Andrew McCoy.
The alternate reality-set "Bones" relates his alternate self healing a broken arm that a young Leonard sustained after falling out of a tree. Later, after his divorce, Leonard discusses with his father how his ex-wife (β) took everything he had.