- Sanderling
- Savanna Hawk
- Savannah Sparrow
- Scaly-breasted Hummingbird
- Scarlet-rumped Cacique
- Scarlet Macaw
- Scarlet Tanager
- Scissor-tailed Flycatcher
- Scrub Euphonia
- Semipalmated Plover
- Sharp-shinned Hawk
- Short-billed Pigeon
- Silver-throated Tanager
- Slaty-tailed Trogon
- Slaty Flowerpiercer
- Smooth-billed Ani
- Snail Kite
- Snow Bunting
- Snow Goose
- Snowy Egret
- Social Flycatcher
- Solitary Sandpiper
- Song Sparrow
- Song Wren
- Sooty-capped Bush Tanager
- Sooty Thrush
- Southern Lapwing
- Southern Mealy Amazon
- Speckled Tanager
- Spectacled Owl
- Spot-breasted Oriole
- Spotted Antbird
- Spotted Sandpiper
- Squirrel Cuckoo
- Stilt Sandpiper
- Stolid Flycatcher
- Streak-backed Oriole
- Streak-chested Antpitta
- Streaked Flycatcher
- Stripe-headed Sparrow
- Stripe-tailed Hummingbird
- Striped Owl
- Summer Tanager
- Swainson's Hawk
- Swainson's Thrush
- Swallow-tailed Kite
- Swamp Sparrow