- Safes and Vaults
- Salt
- Sandblasting
- Saw Sharpening
- Scrap Metal
- Security Alarm Systems
- Security Control Systems
- Self-Storage
- Senior Citizen Service
- Septic Tank Cleaning
- Septic Tank Installation
- Sewer Contractors
- Sewing Machine Stores
- Sheet Metal Work
- Shelving
- Shipping Containers
- Shoe Stores
- Siding Contractors
- Signs
- Snow Removal
- Snowmobiles
- Sod
- Special-Purpose Courses
- Speech-Language Pathologists
- Steel Distributors
- Steel Erectors
- Store Fixtures
- Structural Engineers
- Swimming Pool Contractors
- Swimming Pool Supplies