| IGS PGM cart. |  Ketsui - Kizuna Jigoku-tachi | 2003 | Cave Co., Ltd. Japan |
| Slot Machine | Keystone Cash | 2003 | GTech Corp. Providence, RI, USA |
| Sony PlayStation CD |  Kickboxing Knockout Model SLES-03959 | 2003 | Midas Int. Ent. |
| Slot Machine | Kickin' Keno | 2003 | IGT International Game Technologies Reno, NV, USA |
| Sega Dreamcast GD |  Kidou Senkan Nadesico - Nadesico the Mission Model T-27901M-1 | 2003 | Kadokawa Shoten Japan |
| Bandai WonderSwan Color cart. | Kidou Senshi Gundam - Giren no Yabou - Tokubetsu-Hen - Aoki Hoshi no Hasha Model SWJ-BANC3A | 2003 | Bandai Co., Ltd. Japan |
| Bandai WonderSwan Color cart. | Kidou Senshi Gundam Seed Model SWJ-BANC36 | 2003 | Bandai Co., Ltd. Japan |
| Takara e-Kara MC series cart. | Kids Song Mini Vol. 1 Model MC0005-KSM | 2003 | Takara Co., Ltd. Japan |
| Takara e-Kara MC series cart. | Kids Song Mini Vol. 2 Model MC0008-KSM | 2003 | Takara Co., Ltd. Japan |
| Sony PlayStation CD | Kids Station: Hello Kitty to Album Nikki o Tsukurimasho! Model SLPS-03543 | 2003 | Banpresto Japan |
| Sony PlayStation CD | Kids Station: Hello Kitty to Album Nikki o Tsukurimasho! Model SLPS-03544 | 2003 | Banpresto Japan |
| Takara e-Kara EC series cart. | Kids' Song Best 40 Model EC0084-KSB | 2003 | Takara Co., Ltd. Japan |
| Sega Pico game | Kiki & Lala - Hoshi no Kazu Asobi Model HPC-6133 | 2003 | SEGA Toys |
| Magnavox Odyssey² cart. | Kill the Attacking Aliens | 2003 | XYPE |
| Sony PlayStation 2 disc | kill.switch Model SLUS-20706 | 2003 | NAMCO Hometek, Ltd. USA |
| LeapFrog Leapster cart. | Kindergarten | 2003 | LeapFrog |
| Pachislot | King Camel | 2003 | Sammy Corp. Japan |
| Slot Machine | King Cash 3-Reel | 2003 | Barcrest USA IGT Group USA |
| Slot Machine | King Cash 5-Reel | 2003 | Barcrest USA IGT Group USA |
| Slot Machine | King Classic SL | 2003 | Bally Wulff |
| Pachinko | King God | 2003 | Newgin Japan |
| Sony PlayStation CD | King of Bowling 3 Model SLES-04049 | 2003 | Phoenix Games |
| Slot Machine | King of the Sea | 2003 | Konami Gaming, Inc. Las Vegas, NV, USA |
| 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 |
