| Pachinko |  King Panic - Broad Sword | 2003 | Sanyo Japan |
| Pachinko | King Star | 2003 | Sankyo Tokyo, Japan |
| PC/MS-Windows pack. | King's Land | 2003 | Masula, Jace |
| Slot Machine | Kingdom of Zeus Model ES143 | 2003 | Konami Gaming, Inc. Las Vegas, NV, USA |
| Fruit Machine | Kings & Queens | 2003 | Vivid Gaming England |
| Bandai WonderSwan Color cart. | Kinnikuman IIsei - Choujin Seisenshi Model SWJ-BANC34 | 2003 | Bandai Co., Ltd. Japan |
| Nintendo GBA cart. | Kirby - Nightmare in Dream Land Model AGB-A7KP | 2003 | Nintendo Co., Ltd. Japan |
| Nintendo GameCube disc | Kirby Air Ride Model DOL-GKYE-USA | 2003 | Nintendo of America, Inc. USA 45496 |
| Nintendo GameCube disc | Kirby no Airride Model DOL-GKYJ-JPN | 2003 | Nintendo Co., Ltd. Japan |
| Nintendo GBA cart. | Kisekko Gurumii - Chesty to Nuigurumi-tachi no Mahou no Bouken Model AGB-A2VJ-JPN | 2003 | MTO, Inc. Japan |
| Slot Machine | Knight Moves | 2003 | IGT International Game Technologies Reno, NV, USA |
| Sammy Atomiswave cart. | Knights of Valour - The Seven Spirits | 2003 | IGS Co., Ltd. International Game System |
| PC/MS-Windows CD | KnightShift | 2003 | DreamCatcher Interactive |
| Sinclair ZX Spectrum cass. | Kockapoker Hb | 2003 | NyitraiSOFT |
| Sony PlayStation CD |  Koei Teiban Series: Genghis Khan - Aoki Ookami to Shiroki Mejika IV Model SLPM-87276 | 2003 | KOEI Co., Ltd. Japan |
| Sony PlayStation CD | Koei Teiban Series: Ishin no Arashi - Bakumatsu Shishiden Model SLPM-87277 | 2003 | KOEI Co., Ltd. Japan |
| Sony PlayStation CD | Koei Teiban: Nobunaga no Yabou - Shouseiroku Model SLPM-86376 | 2003 | KOEI Co., Ltd. Japan |
| Sony PlayStation CD | Koei the Best: Genghis Khan - Aoki Ookami to Shiroki Mejika IV Model SLPM-86593 | 2003 | KOEI Co., Ltd. Japan |
| Sony PlayStation CD | Koei the Best: Nobunaga no Yabou - Reppuuden with Power Up Kit Model SLPM-87320 | 2003 | KOEI Co., Ltd. Japan |
| Pachinko | Kogarashi Mon Jirou | 2003 | Heiwa Japan |
| Nintendo GBA cart. | Koinu to Issho - Aijou Monogatari Model AGB-BDIJ-JPN | 2003 | Culture Brain |
| Nintendo GBA cart. | Koinu-chan no Hajimete no Osanpo - Koinu no Kokoro Ikusei Game Model AGB-BISJ-JPN | 2003 | TDK Core |
| DVD Player game | Kokuhaku Model DPG018 18 | 2003 | Guilty Japan |
| Taito G-Net card | Kollon | 2003 | Taito Corp. Japan |
| Sony PlayStation CD | Konami the Best: Captain Tsubasa - Aratanaru Densetsu Joshou Model SLPM-87260 | 2003 | Konami Corp. Japan |
| Nintendo GBA cart. | Konjiki no Gashbell! Unare! Yuujou no Zakeru Model AGB-A4GJ-JPN | 2003 | Banpresto Japan |
| Arcade Video game | Kono e Tako | 2003 | Mitchell Corp. |
| PC/MS-Windows CD | Konung 2 | 2003 | 1C Co. Russia |
| Medal game (video) | Korea World III | 2003 | Korea Elec. |
| Sony PlayStation CD |  Kotobuki Grand Prix Model SLES-04007 | 2003 | Midas Int. Ent. |
| Pachislot | Kouya no Manbou The Magnificent Manbo | 2003 | Olympia Co., Ltd. Japan |
| Pachislot | Kouya no Manbou The Magnificent Manbo At. Art | 2003 | Olympia Co., Ltd. Japan |
| Slot Machine | Krazy Kops | 2003 | Bally Gaming, Inc. Las Vegas, NV, USA |
| PC/MS-Windows CD | Kreed | 2003 | Acclaim Ent., Inc. Glen Cove, NY, USA |
| Takara e-Kara cart. | KSM Mini Vol. 2 Model MC0006-KSM | 2003 | Takara Co., Ltd. Japan |
| Takara e-Kara cart. | KSM Mini Vol. 5 Model MC0013-KSM | 2003 | Takara Co., Ltd. Japan |
| Medal game (video) | KTF II+ | 2003 | Super Electronics Korea |
| Amstrad CPC 464 disk | Ktris Hb | 2003 | Unknown |
| Arcade Video game | Kumyoung Quiz Noraebang | 2003 | Andamiro Co., Ltd. |
| Microsoft XBOX disc | Kung Fu Chaos | 2003 | Unknown |
