- Sanderling
- Savannah Sparrow
- Scaly-breasted Hummingbird
- Scarlet Flycatcher
- Scarlet Macaw
- Scarlet Tanager
- Scissor-tailed Flycatcher
- Scrub Euphonia
- Semipalmated Plover
- Sharp-shinned Hawk
- Silver-throated Tanager
- Slaty Flowerpiercer
- Smooth-billed Ani
- Snow Bunting
- Snow Goose
- Snowy Egret
- Social Flycatcher
- Solitary Sandpiper
- Song Sparrow
- Sooty-capped Bush Tanager
- Sooty Thrush
- Southern Lapwing
- Speckled Tanager
- Spot-breasted Oriole
- Spotted Antbird
- Spotted Sandpiper
- Squirrel Cuckoo
- Stilt Sandpiper
- Stolid Flycatcher
- Streak-backed Oriole
- Stripe-headed Sparrow
- Stripe-tailed Hummingbird
- Summer Tanager
- Swallow-tailed Kite
- Swamp Sparrow