| $350,000–1 million | MATTHEWS TRENCHING CO., INC | OKLAHOMA CITY, OK | RCB Bank |
| $350,000–1 million | MAXWELL SUPPLY COMPANY | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | MAYCO INC. | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MAYES & MAYES OPTOMETRY, PLLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MAZAHERI LAW FIRM PLLC | OKLAHOMA CITY, OK | BancFirst |
| $5–10 million | MCAFEE & TAFT, A PROFESSIONAL CORPORATION | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | MCATTEE & WOODS PC | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | MCCLAIN'S RV SUPERSTORE OKC WEST, INC | OKLAHOMA CITY, OK | Pointbank |
| $350,000–1 million | MCCORKLE TRUCK LINE, INC. | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | MCCOY & ORTA, PC | OKLAHOMA CITY, OK | MidFirst Bank |
| $150,000–350,000 | MCINTYRE LAW P.C. | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | MCV ENTERPRISES, LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MEDALLION RESOURCES, LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MEDIA RESOURCES INC | OKLAHOMA CITY, OK | MidFirst Bank |
| $150,000–350,000 | MEDICAL CENTER PAIN CLINIC, LLC | OKLAHOMA CITY, OK | Arvest Bank |
| $2–5 million | MEDLEY MATERIAL HANDLING COMPANY | OKLAHOMA CITY, OK | International Bank of Commerce |
| $2–5 million | MERCER VALVE CO., INC. | OKLAHOMA CITY, OK | JPMorgan Chase Bank, National Association |
| $150,000–350,000 | MERIDIAN HOTEL LLC | OKLAHOMA CITY, OK | Fidelity Bank, National Association |
| $150,000–350,000 | MERRITT SEALING CO. | OKLAHOMA CITY, OK | Kirkpatrick Bank |
| $150,000–350,000 | MESSIAH LUTHERAN CHURCH, INC. | OKLAHOMA CITY, OK | International Bank of Commerce |
| $350,000–1 million | METHENY CONCRETE PRODUCTS INC. | OKLAHOMA CITY, OK | Prime Bank |
| $350,000–1 million | METRO GLASS, INC. | OKLAHOMA CITY, OK | NBC Oklahoma |
| $150,000–350,000 | METRO GRANITE, LLC | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | METRO RESTAURANT ASSOCIATES, INC | OKLAHOMA CITY, OK | Arvest Bank |
| $350,000–1 million | METRO SIGN CORPORATION | OKLAHOMA CITY, OK | Bank 7 |
| $150,000–350,000 | METRO SURFACES, LLC | OKLAHOMA CITY, OK | Valliance Bank |
| $350,000–1 million | METRO-TECH ELECTRICAL CONTRACT | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | METROPLEX CONSTRUCTION, INC. | OKLAHOMA CITY, OK | First Fidelity Bank |
| $350,000–1 million | METROPOLITAN AIR CONDITIONING CO. | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | MEXICAN RADIO, LLC | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | MI OPS LLC | OKLAHOMA CITY, OK | First Oklahoma Bank |
| $150,000–350,000 | MICHAEL BROOKS-JIMENEZ, P.C. | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | MICHAEL'S GRILL, INC. | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MID AMERICA ROOFING & CONSTRUCTION INC | OKLAHOMA CITY, OK | First National Bank of Oklahoma |
| $150,000–350,000 | MID DEL WINGS LLC | OKLAHOMA CITY, OK | RCB Bank |
| $2–5 million | MID-AMERICA CHRISTIAN UNIVERSITY, INC | OKLAHOMA CITY, OK | CrossFirst Bank |
| $350,000–1 million | MID-CONTINENT GROUP, LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MID-DEL GROUP HOME INC | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | MID-DEL VISION SOURCE, PLLC | OKLAHOMA CITY, OK | Valor Bank |
| $150,000–350,000 | MID-SOUTH CONTRACTING LLC | OKLAHOMA CITY, OK | First Fidelity Bank |
| $150,000–350,000 | MID-STATES WHOLESALE LUMBER CO. | OKLAHOMA CITY, OK | Shamrock Bank, National Association |
| $2–5 million | MID-WEST HOSE & SPECIALTY, INC | OKLAHOMA CITY, OK | BancFirst |
| $2–5 million | MIDCENTRAL ENERGY HOLDINGS LLC | OKLAHOMA CITY, OK | MidFirst Bank |
| $350,000–1 million | MIDSTATE TRAFFIC CONTROL, INC. | OKLAHOMA CITY, OK | MidFirst Bank |
| $150,000–350,000 | MIDWEST CITY FEAST LLC | OKLAHOMA CITY, OK | Security State Bank of Oklahoma |
| $150,000–350,000 | MIDWEST ENGINEERING & TESTING | OKLAHOMA CITY, OK | Valliance Bank |
| $150,000–350,000 | MIDWEST FABRICATORS, LLC | OKLAHOMA CITY, OK | The Central Trust Bank |
| $150,000–350,000 | MIDWEST FLOORING INSTALLATION, LLC | OKLAHOMA CITY, OK | Great Plains National Bank |
| $150,000–350,000 | MIDWEST HOSPITALIST GROUP PLLC | OKLAHOMA CITY, OK | Arvest Bank |
| $350,000–1 million | MIDWEST INSULATION AND MATERIAL LLC | OKLAHOMA CITY, OK | Cross River Bank |
| $150,000–350,000 | MIDWEST NEPHROLOGY GROUP, PLLC | OKLAHOMA CITY, OK | Frontier State Bank |
| $350,000–1 million | MIDWEST WRECKING CO LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MIKE'S INVESTMENTS L.L.C. | OKLAHOMA CITY, OK | Arvest Bank |
| $350,000–1 million | MILAMAR COATINGS, LLC | OKLAHOMA CITY, OK | BMO Bank National Association |
| $350,000–1 million | MILLER-TIPPENS CONSTRUCTION COMPANY, LLC | OKLAHOMA CITY, OK | RCB Bank |
| $150,000–350,000 | MINAL HOTELS LLC | OKLAHOMA CITY, OK | High Plains Bank |
| $150,000–350,000 | MINICK MATERIALS COMPANY | OKLAHOMA CITY, OK | Simmons Bank |
| $150,000–350,000 | MIRACLE PRODUCTION, INC. | OKLAHOMA CITY, OK | BancCentral, National Association |
| $150,000–350,000 | MITCHELL COMMUNICATIONS, INC | OKLAHOMA CITY, OK | Kirkpatrick Bank |
| $2–5 million | MITCHELL CONSULTING SERVICES GROUP INC. | OKLAHOMA CITY, OK | Sovereign Bank |
| $350,000–1 million | MLCV OKLAHOMA, LLC | OKLAHOMA CITY, OK | Woodlands National Bank |
| $150,000–350,000 | MLE SNF OPCO, LLC | OKLAHOMA CITY, OK | Centennial Bank |
| $150,000–350,000 | MMS OKLAHOMA CITY INC | OKLAHOMA CITY, OK | BOKF, National Association |
| $1–2 million | MODULAR SERVICES COMPANY | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MOLECULERA LABS, INC | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | MOLLMAN WATER CONDITIONING, INC. | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | MONTE R LEE AND COMPANY | OKLAHOMA CITY, OK | Kirkpatrick Bank |
| $150,000–350,000 | MONTE'S CLEANERS LLC | OKLAHOMA CITY, OK | First National Bank of Oklahoma |
| $350,000–1 million | MOON CHEMICAL PRODUCTS CO | OKLAHOMA CITY, OK | Sovereign Bank |
| $150,000–350,000 | MOON LAKE INC. | OKLAHOMA CITY, OK | Itria Ventures LLC |
| $150,000–350,000 | MORGAN & ASSOCIATES, P.C. | OKLAHOMA CITY, OK | Legacy Bank |
| $350,000–1 million | MOUNT SAINT MARY HIGHSCHOOL | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | MTH RESTAURANTS, LLC | OKLAHOMA CITY, OK | Truist Bank |
| $2–5 million | MTM RECOGNITION CORPORATION | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | MTZ CONSTRUCTION INC | OKLAHOMA CITY, OK | JPMorgan Chase Bank, National Association |
| $150,000–350,000 | MURRPHY PRODUCTS, INC. | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | MYERS ENGINEERING, CONSULTING ENGINEERS, INC | OKLAHOMA CITY, OK | Prime Bank |
| $350,000–1 million | MYRIAD GARDENS FOUNDATION, INC. | OKLAHOMA CITY, OK | BancFirst |
| $1–2 million | N-VEST, LLC | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | NASH CONSTRUCTION COMPANY | OKLAHOMA CITY, OK | Kirkpatrick Bank |
| $350,000–1 million | NATIONAL COWBOY & WESTERN HERITAGE MUSEUM, INC. | OKLAHOMA CITY, OK | BancFirst |
| $2–5 million | NATIONAL LITIGATION LAW GROUP, LLP | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | NATIONAL LIVESTOCK COMMISSION ASSOCIATION | OKLAHOMA CITY, OK | First United Bank and Trust Company |
| $150,000–350,000 | NATIONAL LOAN INVESTORS LP | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | NATIONAL REINING HORSE ASSOCIATION | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | NECO INDUSTRIES INC | OKLAHOMA CITY, OK | First Bethany Bank & Trust |
| $150,000–350,000 | NEEDHAM & ASSOCIATES PLLC | OKLAHOMA CITY, OK | First Fidelity Bank |
| $150,000–350,000 | NEEDHAM ENERGY LAND SERVICES LLC | OKLAHOMA CITY, OK | First Fidelity Bank |
| $150,000–350,000 | NEEHA HOTELS LLC | OKLAHOMA CITY, OK | High Plains Bank |
| $350,000–1 million | NEEL VETERINARIAN HOSPITAL PC | OKLAHOMA CITY, OK | Bank of Hydro |
| $350,000–1 million | NEESE ENTERPRISES INC | OKLAHOMA CITY, OK | Mabrey Bank |
| $150,000–350,000 | NEIGHBORHOOD SERVICES ORGANIZATION,INC. | OKLAHOMA CITY, OK | InterBank |
| $350,000–1 million | NELSON INDUSTRIAL SERVICES, INC | OKLAHOMA CITY, OK | Prime Bank |
| $150,000–350,000 | NELSON LAWNS, INC | OKLAHOMA CITY, OK | Kirkpatrick Bank |
| $1–2 million | NEUROSCIENCE SPECIALISTS, PC | OKLAHOMA CITY, OK | First Liberty Bank |
| $150,000–350,000 | NEW CENTURY INVESTMENTS VII, LLC | OKLAHOMA CITY, OK | Legacy Bank |
| $350,000–1 million | NEW DIRECTION HOME DIALYSIS, LLC | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | NEXSPACES, LLC | OKLAHOMA CITY, OK | First United Bank and Trust Company |
| $150,000–350,000 | NEXTSTREAM HEAVY OIL, LLC | OKLAHOMA CITY, OK | Kirkpatrick Bank |
| $150,000–350,000 | NIEMANN AND ASSOCIATES, LLC | OKLAHOMA CITY, OK | First Liberty Bank |