- Sabota Lark
- Sacred Kingfisher
- Saddle-billed Stork
- Saffron-crowned Tanager
- Saffron Finch
- Sahul Brush Cuckoo
- Salmon-crested Cockatoo
- Sand-colored Nighthawk
- Sanderling
- Sandhill Crane
- Sandwich Tern
- Sarus Crane
- Satin Bowerbird
- Satyr Tragopan
- Savanna Hawk
- Sayaca Tanager
- Scaled Dove
- Scaled Pigeon
- Scaly-breasted Lorikeet
- Scaly-breasted Munia
- Scaly-feathered Weaver
- Scaly-headed Parrot
- Scarlet-backed Flowerpecker
- Scarlet-chested Sunbird
- Scarlet-headed Blackbird
- Scarlet-rumped Tanager
- Scarlet-rumped Tanager (costaricensis)
- Scarlet Ibis
- Scarlet Macaw
- Scheepmaker's Crowned Pigeon
- Screaming Cowbird
- Secretarybird
- Sedge Warbler
- Semipalmated Plover
- Semipalmated Sandpiper
- Senegal Coucal
- Senegal Thick-knee
- Shikra
- Shining Flycatcher
- Shiny Cowbird
- Shoebill
- Short-billed Dowitcher
- Short-crested Flycatcher
- Short-toed Rock Thrush
- Short-toed Treecreeper
- Siamese Fireback
- Siberian Crane
- Siberian Sand Plover
- Siberian Stonechat
- Silver-beaked Tanager
- Silver-crowned Friarbird
- Silver Gull
- Silver Pheasant
- Silver Teal
- Silvereye
- Silvery-cheeked Hornbill
- Slate-colored Boubou
- Slaty-breasted Wood Rail
- Slaty-tailed Trogon
- Slaty Flowerpiercer
- Slender-billed Gull
- Slender-billed Parakeet
- Small Minivet
- Smew
- Smooth-billed Ani
- Snail Kite
- Snow Bunting
- Snow Goose
- Snowy-crowned Robin-Chat
- Snowy Egret
- Sociable Weaver
- Social Flycatcher
- Solitary Tinamou
- Solomons Corella
- Somali Fiscal
- Somali Ostrich
- Somali Starling
- Song Thrush
- Sooty-headed Bulbul
- South African Shelduck
- South Melanesian Cuckooshrike
- Southern Bald Ibis
- Southern Black Flycatcher
- Southern Brown-throated Weaver
- Southern Carmine Bee-eater
- Southern Cassowary
- Southern Fiscal
- Southern Grey-headed Sparrow
- Southern Ground Hornbill
- Southern Lapwing
- Southern Masked Weaver
- Southern Pochard
- Southern Red Bishop
- Southern Rough-winged Swallow
- Southern Screamer
- Southern Tropical Pewee
- Southern White-crowned Shrike
- Southern White-faced Owl
- Southern Yellow-billed Hornbill
- Spangled Cotinga
- Spangled Drongo
- Speckled Mousebird
- Speckled Pigeon
- Spectacled Eider
- Spectacled Owl
- Spectacled Parrotlet
- Spectacled Weaver
- Speke's Weaver
- Spot-billed Pelican
- Spot-breasted Oriole
- Spotless Starling
- Spotted Dove
- Spotted Flycatcher
- Spotted Owlet
- Spotted Palm Thrush
- Spotted Redshank
- Spotted Sandpiper
- Spotted Thick-knee
- Spotted Tody-Flycatcher
- Spotted Whistling Duck
- Spur-winged Goose
- Spur-winged Lapwing
- Squacco Heron
- Squatter Pigeon
- Squirrel Cuckoo
- Sri Lanka Grey Hornbill
- Sri Lanka Hanging Parrot
- Sri Lanka Scimitar Babbler
- Sri Lanka White-eye
- Star Finch
- Steller's Sea Eagle
- Steppe Eagle
- Stock Dove
- Stork-billed Kingfisher
- Straw-necked Ibis
- Streak-eared Bulbul
- Streaked Flycatcher
- Streaky Seedeater
- Striated Caracara
- Striated Heron
- Striated Pardalote
- Striated Starling
- Stripe-headed Sparrow
- Stripe-tailed Hummingbird
- Stripe-throated Bulbul
- Striped Honeyeater
- Striped Kingfisher
- Stygian Owl
- Sudan Golden Sparrow
- Sula Lorikeet
- Sulawesi Ground Dove
- Sulawesi Hornbill
- Sulphur-crested Cockatoo
- Sulphury Flycatcher
- Sumatran Laughingthrush
- Sumatran Trogon
- Sun Parakeet
- Sunbittern
- Sunda Teal
- Sunda Zebra Finch
- Superb Fairywren
- Superb Fruit Dove
- Superb Lyrebird
- Superb Parrot
- Superb Starling
- Swainson's Sparrow
- Swallow-tailed Gull
- Swamp Boubou
- Swamp Harrier
- Swan Goose
- Swift Parrot
- Swinhoe's Pheasant