| MIA | Veterans Museum and Memorial Center | San Diego, CA | 619 239-2300 |
| Machine Shop | Kenyon Machine, Inc. | San Diego, CA | 858 270-2610 |
| Machine Shop | Lee's Automotive | Lemon Grove, CA | 619 466-1384 |
| Machining | Ceramag Corporation | Escondido, CA | 760 746-5970 |
| Magazine Publisher | Bomber Legends | Ramona, CA | 866 788-3624 |
| Maintenance Programs | Refrigeration Engineering Co. | El Cajon, CA | 619 239-6113 |
| Marine | Omega Fuel Injection | El Cajon, CA | 619 448-3295 |
| Marine Engines | Kenyon Machine, Inc. | San Diego, CA | 858 270-2610 |
| Marketing | Virtual Tour Productions | San Diego , CA | 619 602-2920 |
| Mausoleums | Glen Abbey Memorial Park | Bonita, CA | 877 442-2551 |
| Medical Weight Loss | Coastal Medical Weight Loss Centers | Escondido, CA | 800 884-7546 |
| Medically Supervised Weight Loss | Kind Care Medical Center | Southern California, CA | 866 374-3259 |
| Memorabilia | The San Diego Collection, Inc. | San Diego, CA | 866 308-8023 |
| Memorial Center | Veterans Museum and Memorial Center | San Diego, CA | 619 239-2300 |
| Memorials | Glen Abbey Memorial Park | Bonita, CA | 877 442-2551 |
| Memoriam of Pearl Harbor | Remembering Pearl Harbor | San Diego, CA | 619 294-4411 |
| Milguard | Garland-Fields Glass Company | San Diego, CA | 619 464-1525 |
| Mini Blinds | Sparkle Blinds | San Diego, CA | 619 286-9453 |
| Mirrors | Garland-Fields Glass Company | San Diego, CA | 619 464-1525 |
| Mobile Windshield Replacement | Infinity Auto Glass | San Diego Metro, CA | 877 346-5888 |
| Mortuary | Glen Abbey Memorial Park | Bonita, CA | 877 442-2551 |
| Motor Home Parts and Repairs | San Diego Trailer Supply | San Diego, CA | 619 466-1337 |
| Motor Rebuilding | Hans Meyer's Auto Werkstatt | San Diego, CA | 619 284-6040 |
| Mountain Cabins | Lake Cuyamaca Campgrounds | Cuyamaca, CA | 877 581-9904 |
| Moving | Mudanzas Nacional del Pacifico | Tijuana, Baja California, MX | 664 685-6096 |
| Moving Trailer Rentals | Aztec Rentals | San Diego, CA | 619 582-2245 |
| Mudanzas Internacionales | Mudanzas Nacional del Pacifico | Tijuana, Baja California, MX | 664 685-6096 |
| Mudanzas Nacionales | Mudanzas Nacional del Pacifico | Tijuana, Baja California, MX | 664 685-6096 |
| Mufflers | Ed Hanson's Muffler Service | Spring Valley, CA | 619 698-7030 |
| Multimedia | Virtual Tour Productions | San Diego , CA | 619 602-2920 |
| Museum | Veterans Museum and Memorial Center | San Diego, CA | 619 239-2300 |
| Museum | The San Diego Collection, Inc. | San Diego, CA | 866 308-8023 |
| Mustang | Mustang Auto and Classic Cars | El Cajon, CA | 800 685-8782 |
| Mustang Auto Parts | Mustang Auto and Classic Cars | El Cajon, CA | 800 685-8782 |