| Game Name | System |
|---|
| Twister Club (Crystal) (MPU4) (set 3) | MAME |
| Two Crude (US FT revision 1) | MAME |
| Two Crude (US FT version) | MAME |
| Two Minute Drill | MAME |
| Two Tigers (Tron conversion) | MAME |
| Two Tigers (dedicated) | MAME |
| Tylz (prototype) | MAME |
| Type 'N Talk | MAME |
| Type Zero BIOS | MAME |
| Typhoon | MAME |
| Typhoon Club (Bellfruit) (set 1) (Scorpion 1) | MAME |
| Typhoon Club (Bellfruit) (set 1, Protocol) (Scorpion 1) | MAME |
| U-boat 65 | MAME |
| U.N. Defense Force: Earth Joker (Japan) | MAME |
| U.N. Defense Force: Earth Joker (Japan, prototype?) | MAME |
| U.N. Squadron (USA) | MAME |
| U.S. Championship V'ball (Japan) | MAME |
| U.S. Championship V'ball (US) | MAME |
| U.S. Championship V'ball (bootleg of Japan set) | MAME |
| U.S. Championship V'ball (bootleg of US set) | MAME |
| U.S. Classic | MAME |
| U.S. Navy (Japan 901012) | MAME |
| U.S.A. Football | MAME |
| UFO Catcher 21 | MAME |
| UFO Catcher 800 | MAME |
| UFO Catcher Mini | MAME |
| UFO Master-Blaster Station | MAME |
| UFO-X | MAME |
| UK-2086 ver. 1.2 | MAME |
| UK101 | MAME |
| UKNC | MAME |
| US AAF Mustang (25th May. 1990 / Seoul Trading) | MAME |
| US AAF Mustang (25th May. 1990) | MAME |
| US AAF Mustang (TAB Austria bootleg) | MAME |
| US AAF Mustang (bootleg) | MAME |
| UT-88 | MAME |
| UT-88 mini | MAME |
| UTS-20 | MAME |
| Uchuu Daisakusen: Chocovader Contactee (Japan, CVC1 Ver.A) | MAME |
| Uchuu Tokkyuu Medalian | MAME |
| Ufo Robo Dangar (12/1/1986) | MAME |
| Ufo Robo Dangar (4/07/1987) | MAME |
| Ufo Robo Dangar (9/26/1986) | MAME |
| Ufo Robo Dangar (9/26/1986, Japan) | MAME |
| Ufo Robo Dangar (bootleg) | MAME |
| Ufo Senshi Yohko Chan (MC-8123, 317-0064) | MAME |
| Ufo Senshi Yohko Chan (bootleg, not encrypted) | MAME |
| Ultimate (Dutch) (Bellfruit) (Scorpion 1) | MAME |
| Ultimate Arctic Thunder | MAME |
| Ultimate Arctic Thunder Update CD ver 1.950 (5/3/04) | MAME |
| Ultimate Challenge (Maygay) (M1A/B) (set 1) | MAME |
| Ultimate Challenge (Maygay) (M1A/B) (set 2) | MAME |
| Ultimate Challenge (Maygay) (M1A/B) (set 3) | MAME |
| Ultimate Challenge (Maygay) (M1A/B) (set 4) | MAME |
| Ultimate Ecology (Japan 931203) | MAME |
| Ultimate Mortal Kombat 3 (rev 1.0) | MAME |
| Ultimate Mortal Kombat 3 (rev 1.1) | MAME |
| Ultimate Mortal Kombat 3 (rev 1.2) | MAME |
| Ultimate Nudge (Summit Coin) | MAME |
| Ultimate Tennis | MAME |
| Ultimate Tennis (v 1.4, Japan) | MAME |
| Ultimo (Barcrest) (MPU5) (set 1) | MAME |
| Ultimo (Barcrest) (MPU5) (set 2) | MAME |
| Ultimo (Barcrest) (MPU5) (set 3) | MAME |
| Ultra Balloon | MAME |
| Ultra Invaders | MAME |
| Ultra Maru-hi Mahjong (Japan) | MAME |
| Ultra Tank | MAME |
| Ultra Toukon Densetsu (Japan) | MAME |
| Ultra X Weapons / Ultra Keibitai | MAME |
| Ultra X Weapons / Ultra Keibitai (GAMEST review build) | MAME |
| Ultraman (Japan) | MAME |
| Ultraman Club - Tatakae! Ultraman Kyoudai!! | MAME |
| Ultraman Monster Battle | MAME |
| Umi de Poker / Marine Paradise (Japan) | MAME |
| Uncle Fester's Quest: The Addams Family (PlayChoice-10) | MAME |
| Uncle Poo | MAME |
| Under Defeat (Japan) (GDL-0035) | MAME |
| Under Fire (Japan) | MAME |
| Under Fire (US) | MAME |
| Under Fire (World) | MAME |
| Under Siege (Maygay) (M1A/B) (set 1) | MAME |
| Under Siege (Maygay) (M1A/B) (set 2) | MAME |
| Under Siege (Maygay) (M1A/B) (set 3) | MAME |
| Under Siege (Maygay) (M1A/B) (set 4) | MAME |
| Undercover Cops (Japan) | MAME |
| Undercover Cops (US) | MAME |
| Undercover Cops (World) | MAME |
| Undercover Cops - Alpha Renewal Version | MAME |
| UniWar S | MAME |
| UniWar S (bootleg) | MAME |
| Unibox (Union) (MPU4, set 1) | MAME |
| Unibox (Union) (MPU4, set 2) | MAME |
| Unicorn Dreaming (0100791V, NSW/ACT) | MAME |
| Unicorn Dreaming (0100813V, NSW/ACT) | MAME |
| Unicorn Dreaming (0101228V, New Zealand) | MAME |
| Union Jackpot (JPM) (SYSTEM5, set 1) | MAME |
| Union Jackpot (JPM) (SYSTEM5, set 2) | MAME |
| Union Jackpot (JPM) (SYSTEM5, set 3) | MAME |
| Unior | MAME |
