| Sega Mega Drive cart. |  International Rugby | 1993 | Domark Group, Ltd. |
| Sega Mega Drive cart. | International Superstar Soccer Deluxe Model T-95196-50 P | 1996 | Konami Co., Ltd. Japan |
| Sega Mega Drive cart. | J. League Champion Soccer Model T-105013 | 1993 | Game Arts Co., Ltd. Japan |
| Sega Mega Drive cart. | J. League Pro Striker 2 Model G-5540 | 1994 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | J. League Pro Striker Perfect Model G-5532 | 1993 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | J. League Pro Striker Model G-5526 | 1993 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. |  James 'Buster' Douglas Knockout Boxing P | 1991 | Taito Corp. Japan |
| Sega Mega Drive cart. | James Bond 007 - The Duel Model 043320 | 1992 | Tec Toy Industria de Brinquedos S.A. Brazil |
| Sega Mega Drive cart. | James Bond 007 - The Duel Model T-88016-50 | 1992 | Domark Group, Ltd. |
| Sega Mega Drive cart. | James Pond II - Codename RoboCod Model E199SMXI | 1991 | Electronic Arts CA, USA 14633 |
| Sega Mega Drive cart. | James Pond II - Codename RoboCod Model EM20015 | 1993 | Electronic Arts Victor, Inc. Japan |
| Sega Mega Drive cart. | Janou Touryuumon Model G-4096 P | 1993 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Jantei Monogatari | 1991 | Renovation Products USA |
| Sega Mega Drive cart. | Jashin Draxos | 1993 | Electronic Arts CA, USA 14633 |
| Sega Mega Drive cart. |  Jelly Boy | 199? | Electronic Arts CA, USA 14633 |
| Sega Mega Drive cart. | Jewel Master Model G-4047 | 1991 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Ji Ma Jiang Zhi - Ma Jiang Qing Ren | 199? | Unknown |
| Sega Mega Drive cart. | Jimmy White's Whirlwind Snooker Model T-70206 | 1994 | Virgin Games, Ltd. UK 013715 |
| Sega Mega Drive cart. | Jiu Ji Ma Jiang II - Ye Yan Bian | 1999 | Unknown China |
| Sega Mega Drive cart. | Joe Montana Football II | 1991 | Tec Toy Industria de Brinquedos S.A. Brazil |
| Sega Mega Drive cart. | Joe Montana II - Sports Talk Football Model G-4065 | 1992 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | John Madden Football - Pro Football | 1993 | EA Sports |
| Sega Mega Drive cart. | Ju Ji Ma Jiang II | 199? | Sun Green China |
| Sega Mega Drive cart. | Judge Dredd | 1995 | Acclaim Ent., Inc. Glen Cove, NY, USA |
| Sega Mega Drive cart. | JuJu Densetsu Model G-4064 | 1991 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Junction | 1990 | Micronet Co., Ltd. Japan |
| Sega Mega Drive cart. | Jungle Strike - Uketsugareta Kyouki Model EM20020 | 1993 | Electronic Arts CA, USA 14633 |
| Sega Mega Drive cart. | Junker's High | 1992 | SIMS Co., Ltd. Japan |
| Sega Mega Drive cart. | Jurassic Park - Rampage Edition Model 1557-50 | 1994 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Jurassic Park Model 046040 | 1993 | Tec Toy Industria de Brinquedos S.A. Brazil |
| Sega Mega Drive cart. | Jurassic Park Model 1056-40 | 1993 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Jurassic Park Model 1056-50 | 1993 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Jurassic Park Model G-4109 | 1993 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Juuouki Model G-4001 P | 1988 | SEGA Enterprises, Ltd. Tokyo, Japan |
| Sega Mega Drive cart. | Ka-Ge-Ki Model T-28013 | 1991 | Hot-B Japan |
| Sega Mega Drive cart. | Kawasaki Superbike Challenge Model T-48356-50 | 1995 | Domark Group, Ltd. |
| Sega Mega Drive cart. | Kick Off 3 | 1994 | Imagineer Co., Ltd. Japan |
| Sega Mega Drive cart. | Kick Off 3 - European Challenge Model T-28036 | 1994 | Vic Tokai Japan |
| Sega Mega Drive cart. | Kid Chameleon | 1992 | Tec Toy Industria de Brinquedos S.A. Brazil |
| Sega Mega Drive cart. | Kid Chameleon Model 1010-50 | 1992 | SEGA Enterprises, Ltd. Tokyo, Japan |
