Mega Man II, known as Rockman World 2 (ロックマンワールド2) in Japan, is the second game in the Mega Man World series of side games for the Nintendo Game Boy. It was followed up by Mega Man III in the same year, while the game's story is expanded on in the Japanese only game Rockman & Forte: Mirai Kara no Chōsensha for the WonderSwan.

Like its predecessor, Mega Man: Dr. Wily's Revenge, Mega Man II reuses content from the NES games, both graphics and actual level construction. The first four available Robot Masters and their stages are from Mega Man 2, while the last four are taken from Mega Man 3. The game also introduces many of Mega Man 3's features to the Game Boy series. Mega Man is able to slide. Rush also appears for the first time in the Game Boy series, allowing the use of the Rush Coil, Rush Marine, and Rush Jet. The game also features full stages for the last four Robot Masters, rather than single-room boss fights as in Mega Man: Dr. Wily's Revenge. However, these stages are still accessed via Wily Teleporters, rather than a traditional stage select screen, and special weapon energy does not recharge between these stages. This game is currently available to download on the 3DS Nintendo eShop.