| Coin-op Misc. game |  O.K. | 193? | Genco, Inc. Chicago, IL, USA |
| Coin-op Misc. game | O.K. Twins | 193? | United Amusement Co. Kansas City, MO, USA |
| Coin-op Misc. game | Odd Ball | 193? | Daval Mfg. Co. Chicago, IL, USA |
| Coin-op Misc. game | Odd Clod | 1927 | Bryans Automatic Works Kegworth, Derbyshire, England |
| Coin-op Misc. game | Odd Penny Magnet | 1932 | Stephens & Co., A.J. Kansas City, MO, USA |
| Coin-op Misc. game | Odom Special | 193? | American Sales Co. MO, USA |
| Coin-op Misc. game | Official Soft Ball | 193? | Shyvers Mfg. Co. Chicago, IL, USA |
| Coin-op Misc. game | Official Sweeptakes | 193? | Evans & Co., H.C. Chicago, IL, USA |
| Coin-op Misc. game | Oh Yeah! | 193? | Allswell Mfg. Co. |
| Coin-op Misc. game | Okashi Daisakusen | 1981 | NAMCO, Ltd. Japan |
| Coin-op Misc. game | Old Orchard | 1932 | Automatic Amusement Co., Inc. Los Angeles, CA, USA |
| Coin-op Misc. game | Old Time Basketball | 1975 | Exidy, Inc. Sunnyvale, CA, USA |
| Coin-op Misc. game | Olimpic Hockey | 1985 | Inor |
| Coin-op Misc. game | Olympia | 1952 | Ruhr Automaten |
| Coin-op Misc. game | Olympic | 193? | Evans & Co., H.C. Chicago, IL, USA |
| Coin-op Misc. game | Olympic Ski-Run | 1970 | Nixsons Littlehampton, England |
| Coin-op Misc. game | Olympic Tennis | 19?? | Klingsor-Werke Germany |
| Coin-op Misc. game | One Better | 193? | Rock-Ola Mfg. Corp. Chicago, IL, USA |
| Coin-op Misc. game | One World | 1947 | Amusement Enterprises, Inc. New York, NY, USA |
| Coin-op Misc. game | Onkel Otto | 1953 | POS Automatenbau |
| Coin-op Misc. game | Onkel Theodor | 1905 | Unknown |
| Coin-op Misc. game | Oomph! | 1947 | Daval Products Corp. Chicago, IL, USA |
| Coin-op Misc. game | Open Doors | 193? | International Mutoscope Reel Co., Inc. New York, NY, USA |
| Coin-op Misc. game | Open Season | 193? | ASL Sales Co. |
| Coin-op Misc. game | Operation | 2009 | Coastal Amusements, Inc. Lakewood, NJ, USA |
| Coin-op Misc. game | Optimist | 1936 | Atebe |
| Coin-op Misc. game | Optometer | 1889 | Green, Bruce High Holborn, England |
| Coin-op Misc. game | Orbiting Gemini Ride | 196? | Southland Engineering, Inc. Santa Monica, CA, USA |
| Coin-op Misc. game | Orient | 193? | Western Sales Co. |
| Coin-op Misc. game | Original Balance-Automat | 1930 | Jentzsch & Meerz, Max Leipzig, Germany |
| Coin-op Misc. game | Orleans Blood Pressure Machine | 1959 | Unknown |
| Coin-op Misc. game | Osaru no Kagoya | 1977 | Taito Corp. Japan |
| Coin-op Misc. game | Oscar | 193? | Genco, Inc. Chicago, IL, USA |
| Coin-op Misc. game | Oshaberi Ohm | 1981 | Kato Seisakujo Co., Ltd Japan |
| Coin-op Misc. game | Oshikura Manju | 199? | Komaya Co., Ltd. Japan |
| Coin-op Misc. game | Oumu no Janken Match | 19?? | Unknown Japan |
| Coin-op Misc. game | Outboard | 193? | Daval Mfg. Co. Chicago, IL, USA |
| Coin-op Misc. game | Over and Under | 193? | Daval Mfg. Co. Chicago, IL, USA |
| Coin-op Misc. game | Over the Fence | 193? | Atlas Indicator Works, Inc. Chicago, IL, USA |
| Coin-op Misc. game | Over the Top | 1925 | Boyce Coin Machine Amusement Corp. Tuckahoe, NY, USA |
