| $350,000–1 million | WHITMAN & ASSOCIATES LLC | SAINT LOUIS, MO | St. Louis Bank |
| $150,000–350,000 | WHOLESALE TELECOM INC | SAINT LOUIS, MO | Carrollton Bank |
| $2–5 million | WIES DRYWALL & CONSTRUCTION CORP. | SAINT LOUIS, MO | 1st Advantage Bank |
| $150,000–350,000 | WILKE & WILKE, PC | SAINT LOUIS, MO | U.S. Bank, National Association |
| $350,000–1 million | WILL ELECTRONICS, INC | SAINT LOUIS, MO | Carrollton Bank |
| $2–5 million | WILLERT HOME PRODUCTS, INC. | SAINT LOUIS, MO | Enterprise Bank & Trust |
| $150,000–350,000 | WILSON LIGHTING OF ST LOUIS, INC. | SAINT LOUIS, MO | UMB Bank, National Association |
| $2–5 million | WILSON MANUFACTURING COMPANY | SAINT LOUIS, MO | Enterprise Bank & Trust |
| $150,000–350,000 | WINDSOR GYMNASTICS INSTITUTE, INC. | SAINT LOUIS, MO | Celtic Bank Corporation |
| $350,000–1 million | WINTER BROTHERS MATERIAL COMPANY | SAINT LOUIS, MO | First Bank |
| $150,000–350,000 | WIRED TECHNOLOGIES, INC | SAINT LOUIS, MO | Enterprise Bank & Trust |
| $1–2 million | WM A. STRAUB INC | SAINT LOUIS, MO | Midland States Bank |
| $150,000–350,000 | WM G. COCOS CO., INC. | SAINT LOUIS, MO | Southern Bank |
| $150,000–350,000 | WM HOLDINGS, LLC | SAINT LOUIS, MO | Commerce Bank |
| $150,000–350,000 | WM. MANTIA FRUIT CO., INC. | SAINT LOUIS, MO | Midwest Regional Bank |
| $150,000–350,000 | WOLD CHESS MUSEUM, INC. | SAINT LOUIS, MO | UMB Bank, National Association |
| $350,000–1 million | WOLFE RESTORATION OF ST LOUIS CENTRAL LLC | SAINT LOUIS, MO | Teutopolis State Bank |
| $150,000–350,000 | WOLFF & TAYLOR PC | SAINT LOUIS, MO | Commerce Bank |
| $150,000–350,000 | WOLKEN DENTAL, D.D.S., P.C. | SAINT LOUIS, MO | Busey Bank |
| $150,000–350,000 | WOMEN'S CARE CONSULTANTS, LLC | SAINT LOUIS, MO | Busey Bank |
| $2–5 million | WOOD RIBBLE & TWYMAN INC. | SAINT LOUIS, MO | Busey Bank |
| $2–5 million | WOODARD CLEANING AND RESTORATION INC | SAINT LOUIS, MO | Bank of America, National Association |
| $1–2 million | WOODRUFF COMMUNICATIONS ST. LOUIS LLC | SAINT LOUIS, MO | The Central Trust Bank |
| $150,000–350,000 | WORD OF LIFE LUTHERAN SCHOOL | SAINT LOUIS, MO | PNC Bank, National Association |
| $150,000–350,000 | WORKGROUP CONNECTIONS INC. | SAINT LOUIS, MO | Busey Bank |
| $350,000–1 million | WORKING SPACES, INC. | SAINT LOUIS, MO | Triad Bank |
| $350,000–1 million | WORLD'S FARE MANAGEMENT GROUP, LLC | SAINT LOUIS, MO | Busey Bank |
| $150,000–350,000 | WORTH INDUSTRIES, INC. | SAINT LOUIS, MO | Midwest BankCentre |
| $350,000–1 million | WPHI LLC | SAINT LOUIS, MO | Bank of Washington |
| $150,000–350,000 | WRYMARK, INC. | SAINT LOUIS, MO | Carrollton Bank |
| $350,000–1 million | WUNDERLICH FIBRE BOX CO | SAINT LOUIS, MO | Cass Commercial Bank |
| $350,000–1 million | XCELLOPS | SAINT LOUIS, MO | Peoples National Bank, National Association |
| $150,000–350,000 | XTREME EXHIBITS INC | SAINT LOUIS, MO | U.S. Bank, National Association |
| $150,000–350,000 | XU & WEI LLC | SAINT LOUIS, MO | Carrollton Bank |
| $150,000–350,000 | YA ENGINEERING SERVICES, LLC | SAINT LOUIS, MO | UMB Bank, National Association |
| $150,000–350,000 | YORK MANAGEMENT GROUP, LLC | SAINT LOUIS, MO | Enterprise Bank & Trust |
| $150,000–350,000 | YOUNG MONIES UNLIMITED, INC. | SAINT LOUIS, MO | Commerce Bank |
| $150,000–350,000 | YOUR ESTATE MATTERS LLC | SAINT LOUIS, MO | PNC Bank, National Association |
| $150,000–350,000 | ZAMZOW MANUFACTURING | SAINT LOUIS, MO | Midwest BankCentre |
| $150,000–350,000 | ZEIN GROUP INTERNATIONAL, INC | SAINT LOUIS, MO | Midwest Regional Bank |
| $150,000–350,000 | ZEIS GROUP | SAINT LOUIS, MO | Carrollton Bank |
| $350,000–1 million | ZELLER TECHNOLOGIES, INC. | SAINT LOUIS, MO | Newtek Small Business Finance, Inc. |
| $150,000–350,000 | ZIP CITY INDUSTRIES, LLC | SAINT LOUIS, MO | The Bank of Houston |
| $150,000–350,000 | ZOBRIO INC | SAINT LOUIS, MO | PNC Bank, National Association |
| $150,000–350,000 | ZODIAC, INC. | SAINT LOUIS, MO | Carrollton Bank |
| $350,000–1 million | ZONE ENTERPRISES, LLC | SAINT LOUIS, MO | Carrollton Bank |
| $150,000–350,000 | ZOW LLC | SAINT LOUIS, MO | Plains Commerce Bank |
| $350,000–1 million | ZUMWALT CORPORATION | SAINT LOUIS, MO | Montgomery Bank |