D.O.

D.O. is a post-nominal title. It could stand for
 * D.O., gay porn actor for Black Scorpion Videos.
 * Doctor of Osteopathic Medicine, the less common of the two degrees (M.D. & D.O.) held by licensed physicians in the United States.
 * Diploma of Osteopathy (a type of manual therapy) the degree held by osteopaths outside the United States.