| 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 video game | 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 MC series cart. | KSM Mini Vol. 2 Model MC0006-KSM | 2003 | Takara Co., Ltd. Japan |
| Takara e-Kara MC series cart. | KSM Mini Vol. 5 Model MC0013-KSM | 2003 | Takara Co., Ltd. Japan |
| Medal video game | KTF II+ | 2003 | Super Electronics Korea |
| Amstrad CPC 464 disk | Ktris Hb | 2003 | Unknown |
| Arcade Video game | Kumyoung Quiz Noraebang | 2003 | Andamiro Co., Ltd. |
| Pachinko | Kurun Kurun | 2003 | Ginza Japan |
| Arcade Video game | Kyokyoku Hana no Mai Deluxe | 2003 | Techno-Top, Ltd. Japan |
| LeapFrog Leapster cart. | La Conquista de los Números | 2003 | LeapFrog |
| Sky Gamestar game | Lara Croft Tomb Raider - Apocalypse: Episode 2 - The Shadow Falls | 2003 | Sky Games |
| Sky Gamestar game | Lara Croft Tomb Raider - Apocalypse: Episode 3 - The Last Midnight | 2003 | Sky Games |
| Sinclair ZX Spectrum+3 disk | Las Aventuras de Pepe Trueno Hb | 2003 | Rockersuke Moroboshi |
| PC/MS-Windows CD | Law & Order II - Double or Nothing | 2003 | DreamCatcher Interactive |
| LeapFrog Leappad cart. | Leap 1 - Reading - Disney/Pixar Finding Nemo | 2003 | LeapFrog |
| LeapFrog Leappad cart. | Leap's Pond - Activity & Game Book | 2003 | LeapFrog |
| LeapFrog Leappad cart. | LeapPad Interactive Book | 2003 | LeapFrog |
| Dedicated Console | Leapster | 2003 | LeapFrog |
| LeapFrog Leapster cart. | Learning with Leap | 2003 | LeapFrog |
| PC/MS-Windows CD | Legacy of Kain - Defiance | 2003 | Eidos Interactive |
| Nintendo GBA cart. | Legend of Dynamic Goushouden - Houkai no Rondo Model AGB-AVDJ-JPN | 2003 | Banpresto Japan |
| Sony PlayStation CD | Legend of Mulan Model SLES-04145 | 2003 | Phoenix Games |
| Sony PlayStation 2 disc | Legends of Wrestling II Model SLES-51045 | 2003 | Acclaim Ent., Inc. Glen Cove, NY, USA |
| Slot Machine | Lemon Lime Twist | 2003 | WMS Gaming, Inc. Chicago, IL, USA |
| LeapFrog Leapster cart. | Lernen mit Leap | 2003 | LeapFrog |
