Mega Man 6, known in Japan as Rockman 6: The Greatest Battle in History!!, is a 1993 action-platform game developed by Capcom for the Nintendo Entertainment System. It is the sixth installment in the original Mega Man series. It was originally released in Japan by Capcom in 1993, and in North America by Nintendo in 1994. It was included in the Mega Man Anniversary Collection released in 2004. Its first release in Europe and PAL region was June 11, 2013, for the 3DS Virtual Console, nearly twenty years after the game's initial release.

The story of Mega Man 6 opens during a competitive robot fighting tournament with entrants from all around the globe. A villainous figure known as "Mr. X" announces he has reprogrammed the eight powerful finalists with the intent to use them for taking over the world. The game's robotic protagonist Mega Man, who was sent to oversee the tournament, springs into action to foil X's plot. Mega Man 6 plays nearly identically to its five predecessors with a few added features such as stages with alternate pathways and new Rush adaptors.

Mega Man 6 is the first game in the series to receive character design input from fans outside Japan. This late-era game was also the last in the series released on Nintendo's 8-bit console, and the last game in the series with an 8-bit graphics style until Mega Man 9 in 2008. Due to the declining support of the NES and the growing presence of the newer and more powerful Super Nintendo Entertainment System (SNES), Capcom decided not to publish Mega Man 6 in North America, so it was released by Nintendo in that region. The game received positive reviews, with critics praising the gameplay and use of the established gameplay model from preceding chapters in the series, though it was criticized for not innovating much compared to its predecessors. It was followed up with Mega Man 7, released for the SNES in 1995.

Mega Man 6's story takes place one year or so later after the events of Mega Man 5. To counter Dr. Wily's repeated attacks, the Global Robot Alliance was formed, and one year later the "First Annual Robot Tournament" is held to determine the world's strongest peacekeeping robot. The tournament is hosted by a man known only as "Mr. X," the leader of the mysterious "X Foundation" and many strong robots participate. Dr. Light, a pacifist, decides not to enter the competition, but sends the robotic hero Mega Man to supervise it. Before the event can begin, however, Mr. X announces that he has reprogrammed eight of the strongest contestants to do his bidding in taking over the world: Blizzard Man, Centaur Man, Flame Man, Knight Man, Plant Man, Tomahawk Man, Wind Man, and Yamato Man, and tells Mega Man he had been manipulating Dr. Wily from the beginning.[8] Following this, Mega Man and Rush set out to put an end to Mr. X's plan. Mega Man destroys the eight Robot Masters and then goes to Mr. X's fortress. The villain is beaten and quickly reveals himself as none other than a disguised Dr. Wily. The evil scientist flees to a new fortress stronghold where Mega Man pursues and defeats him again. The game ends with Dr. Wily finally brought to justice and sent to prison