- Sand Martin
- Sanderling
- Sandwich Tern
- Sardinian Warbler
- Savi's Warbler
- Sedge Warbler
- Short-eared Owl
- Short-toed Snake Eagle
- Short-toed Treecreeper
- Slender-billed Gull
- Smew
- Snow Bunting
- Snow Goose
- Song Thrush
- Spanish Sparrow
- Spectacled Warbler
- Spotted Crake
- Spotted Flycatcher
- Spotted Redshank
- Squacco Heron
- Stock Dove
- Swan Goose