- Laboratories Dental, Mercer Island
- Laboratories Medical, Mercer Island
- Land Surveyor, Mercer Island - Land Surveying Services
- Landscape Contractors & Designers, Mercer Island
- Landscaping, Mercer Island
- Lawn & Garden Services, Mercer Island
- Lawn Maintenance Services, Mercer Island
- Lawyers & Attorneys, Mercer Island
- Legal & Tax Services, Mercer Island
- Legal Professionals, Mercer Island
- Libraries, Mercer Island
|
- Life Insurance, Mercer Island
- Liquor Stores, Mercer Island
- Live Theaters, Mercer Island
- Locks, Mercer Island
- Locksmiths, Mercer Island - Residence, Commercial, Safe & Auto Car Locksmith
- Locksmiths Equipment & Supplies, Mercer Island
- Lodging, Mercer Island
- Luggage & Accessories , Mercer Island
- Lumber & Lumber Products, Mercer Island
- Lutheran Church, Mercer Island
|
