- Sabine's Gull
- Saffron Finch
- Sahel Bush Sparrow
- Sahel Paradise Whydah
- Sand Martin
- Sanderling
- Sandhill Crane
- Sandwich Tern
- Santa Marta Antpitta
- Santa Marta Brushfinch
- Santa Marta Bush Tyrant
- Santa Marta Mountain Tanager
- Santa Marta Warbler
- Santa Marta Woodstar
- Sardinian Warbler
- Savanna Hawk
- Savi's Warbler
- Savile's Bustard
- Saxaul Sparrow
- Scaled Dove
- Scaled Fruiteater
- Scaled Piculet
- Scaly-breasted Munia
- Scaly-naped Amazon
- Scaly-sided Merganser
- Scarlet-backed Flowerpecker
- Scarlet-chested Sunbird
- Scarlet Macaw
- Scissor-tailed Flycatcher
- Scissor-tailed Kite
- Scopoli's Shearwater
- Screaming Piha
- Scrub Euphonia
- Scrub Greenlet
- Scrub Tanager
- Sedge Warbler
- Semipalmated Plover
- Semipalmated Sandpiper
- Senegal Coucal
- Senegal Parrot
- Senegal Thick-knee
- Shikra
- Shining-blue Kingfisher
- Shining Sunbeam
- Shiny Cowbird
- Short-crested Flycatcher
- Short-eared Owl
- Short-tailed Hawk
- Short-tailed Nighthawk
- Short-tailed Woodstar
- Short-toed Snake Eagle
- Short-toed Treecreeper
- Siberian Stonechat
- Sickle-winged Guan
- Sierra Nevada Brushfinch
- Silver-beaked Tanager
- Silver-throated Tanager
- Silvery Grebe
- Slate-throated Whitestart
- Slaty-backed Chat-Tyrant
- Slaty-crowned Antpitta
- Slaty-tailed Trogon
- Slaty Brushfinch
- Slender-billed Gull
- Smoke-colored Pewee
- Smooth-billed Ani
- Snail Kite
- Snowy Egret
- Snowy Owl
- Social Flycatcher
- Solitary Eagle
- Song Sparrow
- Song Thrush
- Sooty-headed Bulbul
- Sooty Shearwater
- Southern Beardless Tyrannulet
- Southern Lapwing
- Southern Mealy Amazon
- Spanish Sparrow
- Sparkling Violetear
- Speckled Hummingbird
- Speckled Pigeon
- Spectacled Owl
- Spectacled Warbler
- Spectacled Whitestart
- Spot-breasted Oriole
- Spot-breasted Woodpecker
- Spot-breasted Wren
- Spot-winged Antbird
- Spotless Starling
- Spotted Crake
- Spotted Dove
- Spotted Flycatcher
- Spotted Redshank
- Spotted Sandpiper
- Spotted Tody-Flycatcher
- Spotted Towhee
- Spur-winged Lapwing
- Squacco Heron
- Squirrel Cuckoo
- Steely-vented Hummingbird
- Steller's Jay
- Steppe Eagle
- Stilt Sandpiper
- Stout-billed Cinclodes
- Straight-billed Hermit
- Straight-billed Woodcreeper
- Streak-eared Bulbul
- Streak-headed Woodcreeper
- Streak-throated Bush Tyrant
- Streaked Flycatcher
- Streaked Saltator
- Striated Heron
- Stripe-backed Wren
- Striped Cuckoo
- Strong-billed Woodcreeper
- Subalpine Warbler
- Sudan Golden Sparrow
- Summer Tanager
- Sun Lark
- Superciliated Wren
- Surf Scoter
- Swainson's Thrush
- Swallow-tailed Kite
- Swallow Tanager
- Swamp Flycatcher
- Sword-billed Hummingbird
- Sykes's Warbler
- Syrian Woodpecker