- Sanderling
- Sandhill Crane
- Sandwich Tern
- Savannah Sparrow
- Scarlet Macaw
- Scarlet Tanager
- Scissor-tailed Flycatcher
- Scott's Oriole
- Sedge Wren
- Semipalmated Plover
- Semipalmated Sandpiper
- Sharp-shinned Hawk
- Slaty Flowerpiercer
- Snow Bunting
- Snow Goose
- Snowy Egret
- Snowy Owl
- Solitary Sandpiper
- Song Sparrow
- Sooty-capped Chlorospingus
- Sooty Shearwater
- Sooty Thrush
- Sora
- Spotted Sandpiper
- Spruce Grouse
- Squirrel Cuckoo
- Steller's Jay
- Streak-backed Oriole
- Streaked Flycatcher
- Summer Tanager
- Swainson's Hawk
- Swainson's Thrush
- Swallow-tailed Kite
- Swamp Sparrow
- Swan Goose