- Sage Thrasher
- Salmon-crested Cockatoo
- San Cristobal Mockingbird
- Sandhill Crane
- Saw-billed Hermit
- Say's Phoebe
- Scale-crested Pygmy Tyrant
- Scaly-breasted Thrasher
- Scarlet-chested Parrot
- Scarlet Tanager
- Scott's Oriole
- Sedge Wren
- Sepia-brown Wren
- Sharp-beaked Ground Finch
- Sharp-shinned Hawk
- Sharp-tailed Grouse
- Short-eared Owl
- Sinaloa Wren
- Small Ground Finch
- Small Tree Finch
- Smew
- Snowy Owl
- Snowy Plover
- Socorro Mockingbird
- Socorro Wren
- Song Sparrow
- Song Wren
- Sooty-headed Wren
- Sooty Shearwater
- Southern Martin
- Southern Nightingale-Wren
- Southern Nightingale-Wren (luscinia)
- Speckle-breasted Wren
- Speckled Mousebird
- Spectacled Owl
- Spoon-billed Sandpiper
- Spot-breasted Woodpecker
- Spot-breasted Wren
- Spotted Owl
- Spotted Wren
- Spruce Grouse
- Spur-winged Goose
- Steere's Liocichla
- Stolid Flycatcher
- Streaked Flycatcher
- Streaky Seedeater
- Stripe-backed Wren
- Stripe-breasted Wren
- Stripe-throated Wren
- Stygian Owl
- Sumichrast's Wren
- Summer Tanager
- Sun Parakeet
- Superciliated Wren
- Swainson's Hawk
- Swainson's Warbler
- Swallow-tailed Kite