| Sony PlayStation CD |  Kaitou Apricot Model SLPS-03532 | 2003 | Takuyo Co., Ltd. |
| Sega Dreamcast GD | Kaitou Apricot Model T-37910M | 2003 | Takuyo Co., Ltd. |
| Pachislot | Kaizoku Gappo | 2003 | Eipex Tokyo, Japan |
| Slot Machine | Kaleidoscope | 2003 | WMS Gaming, Inc. Chicago, IL, USA |
| Sega Pico game | Kamen Rider 555 Model T-1334505 | 2003 | Bandai Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Kanji Boy 3 Model CGB-BK3J-JPN | 2003 | J-Wing |
| IVL Easy Karaoke cart. | KaraokeMicro Star Cart. 1 | 2003 | IVL Technologies |
| IVL Easy Karaoke cart. | KaraokeMicro Star Cart. 2 | 2003 | IVL Technologies |
| Nintendo GBA cart. | Kawaii Pet Game Gallery Model AGB-BKGJ-JPN | 2003 | Culture Brain |
| Pachislot | Kaze no Youjimbou | 2003 | Rodeo Corp. Japan |
| Medal video game | KBH 3 | 2003 | Union Bird Korea |
| Slot Machine | Kenosaurus Keno | 2003 | IGT International Game Technologies Reno, NV, USA |
| Dedicated Console | Kenshin Dragon Quest - Yomigaerishi Densetsu no Ken | 2003 | Square Enix Co., Ltd. Japan |
| Pachinko | Kerokero Keroppi | 2003 | Ginza Japan |
| Nintendo GameCube disc | Kerokero King DX | 2003 | Bandai Co., Ltd. Japan |
| 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 cart. | Kids Song Mini Vol. 1 Model MC0005-KSM | 2003 | Takara Co., Ltd. Japan |
| Takara e-Kara 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 cart. | Kids' Song Best 40 Model EC0084-KSB | 2003 | Takara Co., Ltd. Japan |
| Takara e-Kara cart. | Kids' Song Mini Vol. 4 Model MC0011-KSM | 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 |
| Microsoft XBOX disc | Kill.switch | 2003 | Unknown |
| 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 |
