| Nintendo Game Boy Color cart. |  Keitai Denjuu Telefang - Power Version Model DMG-BTXJ-JPN | 2000 | Natsume, Inc. Japan |
| Nintendo Game Boy Color cart. | Keitai Denjuu Telefang - Speed Version Model DMG-BTZJ-JPN | 2000 | Natsume, Inc. Japan |
| Nintendo Game Boy Color cart. | Kelly Club - Clubhouse Fun Model CGB-BKIE-USA | 2001 | Knowledge Adventure, Inc. |
| Nintendo Game Boy Color cart. | Ken Griffey Jr.'s Slugfest Model CGB-AYAE-USA | 1999 | Nintendo of America, Inc. USA 45496 |
| Nintendo Game Boy Color cart. | Kettou Beast Wars - Beast Senshi Saikyou Ketteisen Model DMG-AB7J-JPN | 1999 | Takara Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Kidou Senkan Nadesico - Ruri Ruri Mahjong Model CGB-AQNJ-JPN | 1999 | King Records Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Kikansha Thomas - Sodor-tou no Nakama-tachi Model CGB-BBWJ-JPN | 2001 | Tam Japan |
| Nintendo Game Boy Color cart. | Kindaichi Shounen no Jikenbo - 10nenme no Shoutaijou Model DMG-BKSJ-JPN | 2000 | Banpresto Japan |
| Nintendo Game Boy Color cart. | Kinniku Banzuke GB - Chousensha wa Kimida! Model DMG-A5KJ-JPN | 1999 | Konami Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Kinniku Banzuke GB2 - Mezase! Muscle Champion Model DMG-B6KJ-JPN | 2000 | Konami Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Kinniku Banzuke GB3 - Shinseiki Survival Retsuden! Model DMG-B7KJ-JPN | 2001 | Konami Corp. Japan |
| Nintendo Game Boy Color cart. | Kirby Tilt 'n' Tumble Model CGB-KTNE-USA | 2001 | Nintendo of America, Inc. USA 45496 |
| Nintendo Game Boy Color cart. | Kirikou Model CGB-BKKP-EUR | 2001 | Wanadoo Edition |
| Nintendo Game Boy Color cart. | Kisekae Series 2 - Oshare Nikki Model CGB-B23J-JPN | 2001 | Victor Interactive Soft., Inc. |
| Nintendo Game Boy Color cart. | Kisekae Series 3 - Kisekae Hamster Model CGB-BKHJ-JPN | 2001 | Victor Interactive Soft., Inc. |
| Nintendo Game Boy Color cart. | Klax Model CGB-ALXE-USA | 1999 | Midway Home Ent. |
| Nintendo Game Boy Color cart. |  Klax Model CGB-ALXP-EUR | 1999 | Midway Home Ent. |
| Nintendo Game Boy Color cart. | Klustar Model DMG-AKUE-USA | 1999 | Infogrames Ent., Inc. CA, USA 20295 |
| Nintendo Game Boy Color cart. | Klustar Model DMG-AKUP-EUR | 1999 | Infogrames Europe 546430 |
| Nintendo Game Boy Color cart. | Knockout Kings Model CGB-AXKE-USA | 1999 | EA Sports |
| Nintendo Game Boy Color cart. | Knockout Kings Model CGB-AXKP-EUR | 1999 | EA Sports |
| Nintendo Game Boy Color cart. | Koguru Guruguru - Guruguru to Nakayoshi Model DMG-BKGJ-JPN | 2001 | Sting Japan |
| Nintendo Game Boy Color cart. | Konami GB Collection Vol.1 Model DMG-AF5P-EUR | 2000 | Konami Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Konami GB Collection Vol.2 Model DMG-AF6P-EUR | 2000 | Konami Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Konami GB Collection Vol.3 Model DMG-AF7P-EUR | 2000 | Konami Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Konami GB Collection Vol.4 Model DMG-AF8P-EUR | 2000 | Konami Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Konami Winter Games Model CGB-A3HP-EUR | 2000 | Konami Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Konchuu Fighters Model CGB-BZZJ-JPN | 2002 | Digital Kids |
| Nintendo Game Boy Color cart. | Konchuu Hakase 2 Model DMG-A2KJ-JPN | 1999 | J-Wing |
| Nintendo Game Boy Color cart. | Konchuu Hakase 3 Model CGB-A3KJ-JPN | 2001 | J-Wing |
| Nintendo Game Boy Color cart. | Korokoro Kirby Model CGB-KKKJ-JPN | 2000 | Nintendo Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Koto Battle - Tengai no Morihito Model CGB-BAJJ-JPN | 2001 | AlphaDream Corp. Japan |
| Nintendo Game Boy Color cart. | Kou Dai Guai Shou - Lan Bao Shi | 200? | Sintax China |
| Nintendo Game Boy Color cart. | Kou Dai Yao Guai - Bai Jin Ban | 2005 | Sintax China |
| Nintendo Game Boy Color cart. | Koushien Pocket Model DMG-AKSJ-JPN | 1999 | Magical Co., Ltd. Japan |
| Nintendo Game Boy Color cart. | Lao Fuzi Chuanqi | 200? | Sintax China |
| Nintendo Game Boy Color cart. | Las Super Nenas - El Malvado Mojo Jojo Model CGB-BJJS-ESP | 2000 | BAM! Ent. |
| Nintendo Game Boy Color cart. | Las Super Nenas - Lucha con Ese Model CGB-BBHS-ESP | 2001 | BAM! Ent. |
| Nintendo Game Boy Color cart. | Las Super Nenas - Panico en Townsville Model CGB-BPTS-ESP | 2000 | BAM! Ent. |
| Nintendo Game Boy Color cart. | Las Vegas Cool Hand Model DMG-ACWE-USA | 1998 | Take-Two Interactive |
