Nolan Grayson is the deuteragonist of Invincible, serving as the main antagonist of Season 1.

He is the Viltrumite Supervillain/Anti-Hero Omni-Man and the father of Mark Grayson/Invincible. Husband of Debbie Grayson. Born on the distant planet Viltrum into an imperialistic race of super-beings, Nolan was indoctrinated with the Viltrumite creed of conquering as much of the galaxy as possible to assimilate other worlds, species, and civilizations into the Viltrumite Empire. Nolan joined the Viltrumite military forces as a young man and rapidly rose through their ranks through years of successful war and conquest. Eventually, the size of their ever-growing empire and their forces being spread thin prompted the Viltrumites to look for more efficient methods of galactic domination. To counter the raw man-power needed for a full-scale invasion into target planets, it was instead decided that the most trusted officers of the Viltrumite military would be assigned planets to weaken sufficiently in order to allow for a seamless takeover.