- Sabine's Gull
- Sand Martin
- Sanderling
- Sandwich Tern
- Savi's Warbler
- Sedge Warbler
- Short-eared Owl
- Smew
- Snow Bunting
- Snow Goose
- Snowy Owl
- Sociable Lapwing
- Solitary Sandpiper
- Song Thrush
- Sooty Shearwater
- Sooty Tern
- Spotted Crake
- Spotted Flycatcher
- Spotted Nutcracker
- Spotted Redshank
- Spotted Sandpiper
- Spur-winged Goose
- Squacco Heron
- Steller's Eider
- Stock Dove
- Surf Scoter
- Swallow-tailed Kite