| Name | Phone | Category |
| East Frederick Self Storage | (301) 663-4111 | Moving/Storage |
| EBA Enterprises, Inc. | 301-668-6070 | Construction Management |
| Ecolab | (240) 629-9410 | Cleaning Equipment & Systems |
| EconoLodge | (301) 698-0555 | Lodging/Hotels & Motels |
| ECS Mid-Atlantic | (301) 668-4303 | Engineering Services |
| Eduro Networks, LLC | (240) 529-2000 | Internet/Web Services |
| Edward Jones | 800-441-2357 | Retirement Plan Services |
| e-End | (240) 529-1010 | Recycling Companies |
| J. C. Ehrlich Co., Inc. | (301) 791-6950 | Pest/Rodent Control Companies |
| EKDesigns, LLC | | Web Design |
| Ellen Baker Creative Services | 301-305-4651 | Photographers |
| Ellin & Tucker, Chartered | (301) 696-1926 | Accountants/CPA's |
| EmbroidMe | (301) 631-5321 | Embroidery |
| Emmitsburg Antique Mall/Antique Mall Corporation | (301) 447-6471 | Antiques |
| Emmitsburg Business and Professional Association | | Associations |
| EmpiriStat, Inc. | 240-744-0000 | Biomedical/ Biotechnology |
| Empress Travel | (301) 540-2300 | Travel Agencies |
| Entrepreneur Council of Frederick County | (301) 668-3073 | Non-Profit Organizations |
| Equipment Development Co., Inc. | (301) 663-1600 | Manufactures/Processors |
| Evergreen Graphics Inc. | (301) 662-4795 | Screen Printing |
| Extra Space Self Storage - 115 Wormans | 301-620-8833 | Moving/Storage |
| Extra Space Self Storage - Industry Lane | 301-695-8833 | Moving/Storage |
| Extra Space Self Storage - Main | 301-663-4200 | Moving/Storage |
| ezStorage | (301) 698-4855 | Storage - Household/Commercial |