| $150,000–350,000 | NKAB LLC | OKLAHOMA CITY, OK | Cross River Bank |
| $350,000–1 million | NORTH AMERICAN TIE & TIMBER, LLC | OKLAHOMA CITY, OK | NBC Oklahoma |
| $150,000–350,000 | NORTH CHURCH, INC. | OKLAHOMA CITY, OK | Assemblies of God CU |
| $2–5 million | NORTH OKLAHOMA COUNTY MENTAL HEALTH CENTER | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | NORTH WINDS LIVING CENTER, INC. | OKLAHOMA CITY, OK | InterBank |
| $150,000–350,000 | NUVOLE SV CORP | OKLAHOMA CITY, OK | BancFirst |
| $1–2 million | O&M TB, LLC | OKLAHOMA CITY, OK | Simmons Bank |
| $150,000–350,000 | O'STEEN MEAT SPECIALTIES, INC. | OKLAHOMA CITY, OK | Arvest Bank |
| $350,000–1 million | O2 CONCEPTS, LLC | OKLAHOMA CITY, OK | Vast Bank, National Association |
| $150,000–350,000 | OAKWOOD PROPERTY MANAGEMENT, LLC | OKLAHOMA CITY, OK | First Bethany Bank & Trust |
| $1–2 million | OBJECTSTREAM, INC. | OKLAHOMA CITY, OK | Bank of America, National Association |
| $150,000–350,000 | OBSTETRICS & GYNECOLOGY SPECIALISTS, INC. | OKLAHOMA CITY, OK | Simmons Bank |
| $150,000–350,000 | OCEAN DENTAL CORPORATE OFFICE, INC. | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OCEAN DENTAL OF ARKANSAS, PC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OCEAN DENTAL OF IOWA, PC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OCEAN DENTAL OF TEXAS, PC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OCEAN DENTAL, CHAD HOECKER, DDS, PC | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | OCEAN DENTAL, PC | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | OCT EQUIPMENT LLC | OKLAHOMA CITY, OK | Prosperity Bank |
| $150,000–350,000 | OILFIELD SPECIALTY DISTRIBUTORS, INC. | OKLAHOMA CITY, OK | First United Bank and Trust Company |
| $150,000–350,000 | OK FONDUE, LLC | OKLAHOMA CITY, OK | First Oklahoma Bank |
| $150,000–350,000 | OK SUB OF OKC, INC | OKLAHOMA CITY, OK | The First National Bank and Trust Co, Chickasha, Oklahoma |
| $350,000–1 million | OKC AUTO WORKS, LLC | OKLAHOMA CITY, OK | Bank of Hydro |
| $150,000–350,000 | OKC ELECTRICAL CONTRACTORS, INC. | OKLAHOMA CITY, OK | Prosperity Bank |
| $350,000–1 million | OKC METRO ALLIANCE | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OKC SMILES, LLC | OKLAHOMA CITY, OK | First United Bank and Trust Company |
| $350,000–1 million | OKC-OMS HOLDINGS, PLLC | OKLAHOMA CITY, OK | Valliance Bank |
| $350,000–1 million | OKLAHOMA AGENTS ALLIANCE, LLC | OKLAHOMA CITY, OK | Sovereign Bank |
| $350,000–1 million | OKLAHOMA AUTO EXCHANGE, LLC | OKLAHOMA CITY, OK | BOKF, National Association |
| $1–2 million | OKLAHOMA BAPTIST HOMES FOR CHILDREN, INC. | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | OKLAHOMA BUILDING SERVICES INC | OKLAHOMA CITY, OK | First Fidelity Bank |
| $350,000–1 million | OKLAHOMA CITY BOATHOUSE FOUNDATION | OKLAHOMA CITY, OK | Frontier State Bank |
| $150,000–350,000 | OKLAHOMA CITY EQUINE CLINIC PC | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | OKLAHOMA CITY GYNECOLOGY & OBSTETRICS LLC | OKLAHOMA CITY, OK | UMB Bank, National Association |
| $350,000–1 million | OKLAHOMA CITY NATIONAL MEMORIAL FOUNDATION | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | OKLAHOMA CITY ORTHOPEDICS AND SPORTS MEDICINE, PLLC | OKLAHOMA CITY, OK | INTRUST Bank, National Association |
| $150,000–350,000 | OKLAHOMA COMMUNITY HEALTH CENTERS, INC. | OKLAHOMA CITY, OK | Simmons Bank |
| $350,000–1 million | OKLAHOMA CONTEMPORARY ARTS CENTER | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OKLAHOMA CONTRACTORS SUPPLY, LLC | OKLAHOMA CITY, OK | The Security National Bank of Enid |
| $150,000–350,000 | OKLAHOMA COUNCIL OF PUBLIC AFFAIRS INC | OKLAHOMA CITY, OK | First National Bank of Oklahoma |
| $150,000–350,000 | OKLAHOMA DISTRICT COUNCIL OF THE ASSEMBLIES OF GOD OF THE ST | OKLAHOMA CITY, OK | Kirkpatrick Bank |
| $5–10 million | OKLAHOMA FARM BUREAU MUTUAL INSURANCE CO. | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OKLAHOMA FIRE PROTECTION LLC | OKLAHOMA CITY, OK | Sovereign Bank |
| $350,000–1 million | OKLAHOMA GENERAL AGENCY, INC. | OKLAHOMA CITY, OK | Regent Bank |
| $150,000–350,000 | OKLAHOMA HALL OF FAME | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OKLAHOMA LEGAL COPIES INC LLC | OKLAHOMA CITY, OK | Horizon Bank SSB |
| $150,000–350,000 | OKLAHOMA LITHOTRIPTER ASSOC. L.C. | OKLAHOMA CITY, OK | Regent Bank |
| $350,000–1 million | OKLAHOMA LUBE ASSOCIATES LP | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | OKLAHOMA MUSEUM OF ART, INC | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | OKLAHOMA NATIONAL STOCK YARDS COMPANY | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | OKLAHOMA OTOLARYNGOLOGY ASSOCIATES, LLC | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | OKLAHOMA OTOLARYNGOLOGY HEARING CENTER INC | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | OKLAHOMA PAIN MANAGEMENT, LLC | OKLAHOMA CITY, OK | First Liberty Bank |
| $150,000–350,000 | OKLAHOMA PAIN PHYSICIANS, P.C. | OKLAHOMA CITY, OK | Simmons Bank |
| $350,000–1 million | OKLAHOMA PHILHARMONIC SOCIETY, INC | OKLAHOMA CITY, OK | First Fidelity Bank |
| $150,000–350,000 | OKLAHOMA PREMIER SIGN COMPANY LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OKLAHOMA RADIOLOGY GROUP, PC | OKLAHOMA CITY, OK | Prosperity Bank |
| $350,000–1 million | OKLAHOMA REPOSSESSORS, LLC | OKLAHOMA CITY, OK | First Fidelity Bank |
| $150,000–350,000 | OKLAHOMA RESTAURANT ASSOCIATION | OKLAHOMA CITY, OK | Itria Ventures LLC |
| $1–2 million | OKLAHOMA ROOFING & SHEET METAL LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OKLAHOMA SECONDARY SCHOOL ACTIVITIES ASSOCIATION | OKLAHOMA CITY, OK | UMB Bank, National Association |
| $150,000–350,000 | OKLAHOMA SHIRT COMPANY LLC | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | OKLAHOMA SPORTING SUPPLIES INC. | OKLAHOMA CITY, OK | INTRUST Bank, National Association |
| $1–2 million | OKLAHOMA STATE FAIR, INC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | OKLAHOMA STATE SCHOOL BOARDS ASSOCIATION INC. | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | OKLAHOMA SURGICAL GROUP PLLC | OKLAHOMA CITY, OK | Simmons Bank |
| $2–5 million | OKLAHOMA TEMPORARY SERVICE INC | OKLAHOMA CITY, OK | MidFirst Bank |
| $150,000–350,000 | OKLAHOMA TRANSMISSION SUPPLY, INC. | OKLAHOMA CITY, OK | First United Bank and Trust Company |
| $150,000–350,000 | OKLAHOMA VISUAL GRAPHICS, LLC | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | OKLAHOMA WATERPROOFING COMPANY | OKLAHOMA CITY, OK | Wells Fargo Bank, National Association |
| $150,000–350,000 | OKLAND OIL COMPANY | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | OKX LOGISTICS, INC. | OKLAHOMA CITY, OK | First Fidelity Bank |
| $350,000–1 million | OLC, INC | OKLAHOMA CITY, OK | The Central Trust Bank |
| $350,000–1 million | OLD SURETY LIFE INSURANCE COMPANY | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | OLSON NEAVES & COMPANY PC | OKLAHOMA CITY, OK | Regent Bank |
| $150,000–350,000 | OMEGA DEVELOPMENT COMPANY LLC | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | ONE ELECTRIC LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | ONSITE CONSTRUCTION GROUP, LLC | OKLAHOMA CITY, OK | Bank 7 |
| $350,000–1 million | OPECO, INC. | OKLAHOMA CITY, OK | First Bethany Bank & Trust |
| $1–2 million | OPTIONONE, LLC | OKLAHOMA CITY, OK | First Liberty Bank |
| $350,000–1 million | ORAL AND MAXILLOFACIAL ASSOCIATES, LLC | OKLAHOMA CITY, OK | Simmons Bank |
| $350,000–1 million | ORANGE LEAF HOLDINGS LLC | OKLAHOMA CITY, OK | Legacy Bank |
| $1–2 million | ORANGE POWER GROUP, LLC | OKLAHOMA CITY, OK | Commerce Bank |
| $350,000–1 million | ORDER-MATIC ELECTRONICS CORP LLC | OKLAHOMA CITY, OK | BOKF, National Association |
| $150,000–350,000 | ORIGIN RESOUCE GROUP HOLDINGS, LLC | OKLAHOMA CITY, OK | BancFirst |
| $150,000–350,000 | ORIONNET SYSTEMS LLC | OKLAHOMA CITY, OK | First United Bank and Trust Company |
| $350,000–1 million | ORRKLAHOMA CENTRAL, LLC | OKLAHOMA CITY, OK | Arvest Bank |
| $350,000–1 million | ORRKLAHOMA MOTORS, INC. | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | ORRKLAHOMA WEST, LLC | OKLAHOMA CITY, OK | Arvest Bank |
| $150,000–350,000 | ORTHOPEDIC SPINE ASSOCIATES LLC | OKLAHOMA CITY, OK | First Liberty Bank |
| $350,000–1 million | OSEBERG, INC. | OKLAHOMA CITY, OK | Banc of California |
| $150,000–350,000 | OSO ON PASEO, LLC | OKLAHOMA CITY, OK | MidFirst Bank |
| $350,000–1 million | OSWALT EQUIPMENT COMPANY | OKLAHOMA CITY, OK | First Oklahoma Bank |
| $350,000–1 million | OT CAP PARTNERS, LLC | OKLAHOMA CITY, OK | SpiritBank |
| $350,000–1 million | OTOE-MISSOURIA DEVELOPMENT AUTHORITY | OKLAHOMA CITY, OK | BOKF, National Association |
| $350,000–1 million | OTOLOGIC MEDICAL CLINIC INC | OKLAHOMA CITY, OK | First Bethany Bank & Trust |
| $350,000–1 million | OU E. SUITES, LLC | OKLAHOMA CITY, OK | BancFirst |
| $350,000–1 million | OUTBACK CUSTOMS, LLC | OKLAHOMA CITY, OK | The First National Bank and Trust Co, Chickasha, Oklahoma |
| $150,000–350,000 | OVERHEAD DOOR OF OKLAHOMA, INC | OKLAHOMA CITY, OK | INTRUST Bank, National Association |
| $2–5 million | OZARK PIZZA COMPANY, LLC | OKLAHOMA CITY, OK | Valor Bank |