- Shopsmith
- Shoptoit
- Shoptiques
- Shortrun Posters
- Show Pony Seattle
- SHUKR
- Shula's
- Shutter Medic
- Shtrands
- Sid Mashburn
- Siebert Realty
- Sierra Club
- Sierra Springs
- SIGG
- Sightbox
- Sign4X
- Signature Announcements
- Signature Filing
- Silhouette Design Store
- Silicon Beach Digital
- Silicon Mountain
- Silk Therapeutics
- Silk Naturals
- Silver Cross
- Silver.com
- Silver Phantom Jewelry
- Simon Miller
- Simms Fishing
- Simonson's Salon & Spa
- Simple Sugars
- SIMPLE Mobile
- Simple Contacts
- SimpleHost
- Simply Audiobooks
- Simpli Home
- Simply Framed
- Simply Tall
- Simply Transformative
- Simvoly
- Sincerely
- SimplyProtein
- SingleCare
- SingleParentMeet
- SinoFresh
- SiO Beauty
- Site Skills
- SiteGround UK
- SiteLock
- Sitey
- Sitter.com
- Sittin Easy
- SIX Nutrition
- Sixthman
- Skar Audio
- SketchBox
- SketchUp
- Ski Country Sports
- Ski Rentals
- Skill Silo
- Skin-Etc
- Skincential Sciences
- SkinCeuticals
- Skinny Tan
- SkinSolutions.MD
- SkinnyMint
- Skip the Drive
- Sky-Seller
- Sky Zone Trampoline Park
- SkyAuction.com
- Skylar
- Skyline Chili
- Skylink Home
- SkyLux Travel
- SkyTrak
- Skyroam
- Sleek Nail
- SleekEZ
- Sleepon
- SleepRight
- Slice