| Name | Phone | Category |
| K. Hovnanian Homes | (301) 683-6305 | Construction/Residential |
| Kahley Marketing & Events, LLC | (301) 473-5367 | Marketing/Promotion |
| Kaiser Permanente | (240) 529-1701 | Health Insurance |
| Kalkreuth Roofing & Sheet Metal | (301) 698-0717 | Roofing/Waterproofing Materials |
| Kaplan University - Frederick Campus | (301) 682-4882 | Schools/Colleges |
| Karlys Kline | (240) 357-6400 | Individuals |
| Kathy Schultze State Farm Insurance | (301) 694-6711 | Insurance Agencies/ Brokers |
| Keeney & Basford P.A. Funeral Home | (301) 662-2175 | Funerals/Cemeteries |
| Keller Stonebraker Insurance, Inc. | (301) 644-4463 | Insurance Agencies/ Brokers |
| The Kelley Allstate Agency | 301-662-4400 | Financial Services |
| Kewl Tours & Charters | (301) 898-8628 | Bus Tours & Charters |
| Key Financial Group LLC | 240.215.4709 | Financial Planning |
| Kimberly S. Chaney CPA LLC | (240) 818-2187 | Accountants/CPA's |
| KISCAL, LLC | 301-898-0680 | |
| Kiwanis Club of Suburban Frederick | 301-304-0419 | Non-Profit Organizations |
| Kline, Scott, Visco Commercial Real Estate | (301) 694-8444 | Real Estate Companies |
| Klinger & Associates, Inc. | 301-428-4935 | Insurance Agencies/ Brokers |
| Konica Minolta Business Solution | (410) 712-4144 | Office Equipment/Supplies |
| Korean Martial Arts | 301-620-7171 | Self-Defense |