Grandmaster was created by Roy Thomas and Sal Buscema.
He is shown to own the space station Conjunction. In the episode "Space Cowboys", the Grandmaster and the Collector are revealed to be brothers, just as in Ultimate Spider-Man, both trying to kill each other. After the Collector tries to kill the Grandmaster with Moombas that explode if they eat anything other then grass the Grandmaster hires the Ravagers to bring the Moombas to Knowhere.
During the credits of Guardians Of The Galaxy Vol. 2, the Grandmaster can be seen dancing along to the music playing in the credits.
The Grandmaster appears as the hedonistic ruler of Sakaar. He hosts the Contest of Champions, gladiatorial fights where he subjects interdimensional life-forms into fighting each other nearly to death. Prior to the film, the Grandmaster took in Valkyrie as one of his collectors for potential gladiators. When Thor and Loki arrive on Sakaar, Loki (who came two weeks prior to Thor) wins Grandmaster's favor and becomes Grandmaster's ally. Thor is sent to fight in the Contest of Champions where the Grandmaster informs him that should Thor win against his champion, he would be freed.
At the arena, Grandmaster watches from his cabinet and learns that his champion, the Hulk, is an old ally of Thor. Thor tries to calm the Hulk down, but the two soon engage in a fight. Thor almost defeats Hulk; however, the Grandmaster sabotages the fight by activating Thor's obedience disk, leaving Thor weakened and allowing Hulk to win the fight. Despite Hulk's victory, Thor is spared and instead held captive by the Grandmaster. Soon, however, Thor escapes with the Hulk and manages to turn him back into Bruce Banner. Believing that the Hulk's disappearance is because Thor kidnapped him, the Grandmaster announces that his forces will be hunting down Thor.
The Grandmaster sends Valkyrie and Loki to find Thor and Hulk, but Valkyrie decides to help Thor and Banner liberate the other gladiators, while Loki tags along for convenience. With an uprising on his hands, the Grandmaster orders the people and his bodyguards to not let Thor and his comrades leave the planet. His plot is unsuccessful, and the Grandmaster's empire is overturned by the revolution. After being found by the rebels, the Grandmaster tries to convince them to thank him, claiming that without him, they would have nothing to rebel against.
In the Collector's Collection, there is a portrait of both him and the Collector together. The two seem to be playing a game, with the Grandmaster throwing the game pieces from the table, seeming to show an extremely competitive trait to him.
In the comics and Guardians of the Galaxy cartoon series he has blue skin, where in the Marvel Cinematic universe he has white skin.