- Bullfrog Productions releases Populous on June 5, 1989, which was one of the first commercially successful god games.
- Namco releases Winning Run; Rompers; Blast Off, which is the sequel to Bosconian; Valkyrie no Densetsu; Dirt Fox; World Stadium '89; Finest Hour; Burning Force; Winning Run Suzuka GP; Four Trax; Dangerous Seed and Marvel Land.
- Maxis releases Will Wright's SimCity, the first of the "Sim" games and a revolutionary real-time software toy.
- Tengen releases an unlicensed version of the Tetris video game, which is recalled after Nintendo sues Tengen.
- Wes Cherry writes Solitaire and Robert Donner writes Minesweeper, which are bundled with Microsoft Windows starting from version 3.
- Brøderbund releases the Prince of Persia game, the first in a series of games, noted for its advancements in animation.
- Nintendo of America introduces Enix's Dragon Quest franchise to North America under the name Dragon Warrior.
- Techno Soft releases Herzog Zwei (Mega Drive/Genesis) in Japan, marking an important development in the real-time strategy genre.
- Psygnosis release Shadow of the Beast, demonstrating the capabilities of the Amiga and helping sales of the computer.
- Strategic Studies Group releases Warlords on December 6, 1989, which was one of the first fantasy turn-based strategy game.
- Electronic Arts releases John Madden Football for the Apple II, starting its highly successful line of American football games. It is also the first major football game to feature full 11-man teams.
- Atari Corp. releases the Lynx handheld console.
- Mattel, Inc. releases the Power Glove controller for the NES home console.
- Nintendo releases the Game Boy handheld console, first handheld with cartridges.
- NEC's PC Engine released in North America as the Turbografx-16.
- Sega Mega Drive released in North America as the Sega Genesis.
- Hasbro, Inc. acquires elements of Coleco Industries, Inc.
- Trinity Acquisition Corporation founded (renamed THQ in 1990)
- Nintendo of America, Inc. vs. Tengen
- Nintendo sues Tengen over the Tetris video game copyrights. Tengen loses and recalls all its Tetris games.
- November - Nintendo sues Tengen over production of unlicensed Nintendo games. Tengen loses. (Tengen originally sued Nintendo on December 12, 1988 for antitrust violations.)
- Nintendo v. Camerica Ltd. Nintendo sues Camerica over patent violations related to the Game Genie for the NES console. Camerica wins the suit.
- Nintendo in business for 100 years.