- Games & Hobbies, Catonsville
- Garage Doors & Door Operating Devices, Catonsville
- Garage Doors & Gates, Catonsville - Stores & Companies - Install & Repair Services
- Garage, Door & Window Products, Catonsville
- Garbage & Rubbish Removal, Catonsville
- Garment & Linen Services, Catonsville
- Gas Companies, Catonsville
- Gas Detection, Asbestos & Lead Contractors, Catonsville
- Gas Station, Catonsville - Service & Filling Station
- Gasoline, Catonsville
- Gastroenterologists, Catonsville - GI Doctors, Physicians & Surgeons (Gastroenterology)
- Gemologists & Jewelers, Catonsville
- General Business Consulting, Catonsville
- General Business Services, Catonsville
- General Consultants, Catonsville
- General Management Consulting Services, Catonsville - Management Consultants
- General Merchandise Stores, Catonsville
- General Surgeons, Catonsville - General Surgery Doctors, Physicians & Surgeons
- General Travel Agents & Agencies, Catonsville
- Gift Baskets, Catonsville
- Gift Shops, Catonsville - Gift, Novelty & Souvenir Stores
|
- Gifts By Type & Occasion, Catonsville
- Gifts, Cards & Stationery Stores, Catonsville
- Glass & Glass Products, Catonsville
- Glass & Glazing Contractors, Catonsville
- Glass - Auto, Float, Plate, Window & Doors, Catonsville
- Glass Block & Architectural, Catonsville
- Glass Tinting & Coating, Catonsville - Home - Car Window Tinting
- Glassware & Chinaware Repair, Catonsville
- Global Restaurant, Catonsville
- Golf Clubs Private, Catonsville
- Golf Courses, Catonsville
- Golf Equipment & Supplies Stores, Catonsville - Golf Clubs, Balls, Carts, Bags, Apparel, Shoes & Accessories
- Gourmet Food Stores, Catonsville
- Gourmet Restaurants, Catonsville
- Government, Catonsville
- Graphic Design Services, Catonsville - Graphic Designer
- Graphic Designer & Artist Services, Catonsville
- Greeting Card Stores, Catonsville
- Grocery Stores & Supermarkets, Catonsville
- Ground Transportation, Except Passenger, Catonsville
|