- Sand Martin
- Sanderling
- Sandwich Tern
- Sardinian Warbler
- Sedge Warbler
- Semipalmated Sandpiper
- Sharp-tailed Sandpiper
- Short-eared Owl
- Short-toed Snake Eagle
- Short-toed Treecreeper
- Slender-billed Gull
- Snow Bunting
- Solitary Sandpiper
- Song Thrush
- Spanish Imperial Eagle
- Spanish Sparrow
- Spectacled Warbler
- Spotless Starling
- Spotted Crake
- Spotted Flycatcher
- Spotted Redshank
- Spotted Sandpiper
- Squacco Heron
- Stock Dove