- Sabine's Gull
- Sabota Lark
- Sacred Kingfisher
- Saddle-billed Stork
- Saffron Finch
- Sahel Bush Sparrow
- Sahul Sunbird
- Saker Falcon
- Sanderling
- Sandhill Crane
- Sandwich Tern
- Sardinian Warbler
- Sarus Crane
- Savanna Hawk
- Sayaca Tanager
- Scaled Dove
- Scaly-breasted Munia
- Scaly-feathered Weaver
- Scaly-headed Parrot
- Scaly Ground Roller
- Scaly Spurfowl
- Scarlet-chested Sunbird
- Scarlet Flycatcher
- Scarlet Macaw
- Scarlet Robin
- Schlegel's Asity
- Scissor-tailed Kite
- Scissor-tailed Nightjar
- Scopoli's Shearwater
- Screaming Cowbird
- Secretarybird
- Sedge Warbler
- Semipalmated Plover
- Senegal Batis
- Senegal Coucal
- Senegal Lapwing
- Senegal Parrot
- Senegal Thick-knee
- Serendib Scops Owl
- Shaft-tailed Whydah
- Shikra
- Shining Flycatcher
- Shiny Cowbird
- Shoebill
- Short-billed Gull
- Short-toed Rock Thrush
- Short-toed Snake Eagle
- Sichuan Leaf Warbler
- Sickle-billed Vanga
- Silver Gull
- Silver Teal
- Silvereye
- Silvery-cheeked Hornbill
- Silvery Grebe
- Singing Cisticola
- Sirkeer Malkoha
- Slate-colored Boubou
- Slaty Bunting
- Slender-billed Gull
- Slender-billed Weaver
- Slender-tailed Nightjar
- Small Ground Finch
- Small Minivet
- Smooth-billed Ani
- Snail Kite
- Snow Bunting
- Snow Goose
- Snow Pigeon
- Snowy-crowned Robin-Chat
- Snowy Albatross
- Snowy Egret
- Snowy Owl
- Snowy Plover
- Snowy Sheathbill
- Sociable Weaver
- Soft-plumaged Petrel
- Solitary Sandpiper
- Somali Bee-eater
- Somali Courser
- Somali Ostrich
- Sombre Greenbul
- Song Sparrow
- Song Thrush
- Sooty Albatross
- Sooty Bushtit
- Sooty Chat
- Sooty Oystercatcher
- Sooty Shearwater
- Souimanga Sunbird
- South African Shelduck
- South American Tern
- South Polar Skua
- Southern Black Flycatcher
- Southern Black Korhaan
- Southern Carmine Bee-eater
- Southern Cassowary
- Southern Crested Guineafowl
- Southern Fiscal
- Southern Fulmar
- Southern Giant Petrel
- Southern Grey-headed Sparrow
- Southern Ground Hornbill
- Southern Lapwing
- Southern Masked Weaver
- Southern Pied Babbler
- Southern Pochard
- Southern Red-billed Hornbill
- Southern Red Bishop
- Southern Rough-winged Swallow
- Southern Royal Albatross
- Southern Screamer
- Southern White-crowned Shrike
- Southern Yellow-billed Hornbill
- Spanish Imperial Eagle
- Speckle-fronted Weaver
- Speckle-throated Woodpecker
- Speckled Mousebird
- Speckled Pigeon
- Speckled Tinkerbird
- Spectacled Tyrant
- Spectacled Warbler
- Spectacled Weaver
- Speke's Weaver
- Spike-heeled Lark
- Spix's Guan
- Spix's Spinetail
- Spot-bellied Eagle-Owl
- Spot-billed Pelican
- Spot-flanked Barbet
- Spot-winged Pigeon
- Spot-winged Thrush
- Spotless Starling
- Spotted Crake
- Spotted Dove
- Spotted Eagle-Owl
- Spotted Flycatcher
- Spotted Nothura
- Spotted Owlet
- Spotted Palm Thrush
- Spotted Redshank
- Spotted Sandpiper
- Spotted Thick-knee
- Spotted Towhee
- Spruce Grouse
- Spur-winged Goose
- Spur-winged Lapwing
- Squacco Heron
- Square-tailed Bulbul
- Square-tailed Nightjar
- Squatter Pigeon
- Squirrel Cuckoo
- Sri Lanka Bay Owl
- Sri Lanka Blue Magpie
- Sri Lanka Bush Warbler
- Sri Lanka Drongo
- Sri Lanka Frogmouth
- Sri Lanka Green Pigeon
- Sri Lanka Grey Hornbill
- Sri Lanka Hanging Parrot
- Sri Lanka Hill Myna
- Sri Lanka Junglefowl
- Sri Lanka Scimitar Babbler
- Sri Lanka Spurfowl
- Sri Lanka Swallow
- Sri Lanka Thrush
- Sri Lanka Whistling Thrush
- Sri Lanka White-eye
- Sri Lanka Wood Pigeon
- Sri Lanka Woodshrike
- Steel-blue Whydah
- Steller's Jay
- Steppe Eagle
- Stone Partridge
- Stork-billed Kingfisher
- Stout Cisticola
- Straneck's Tyrannulet
- Straw-necked Ibis
- Streaked Weaver
- Streaked Xenops
- Streaky Seedeater
- Streamer-tailed Tyrant
- Striated Heron
- Stripe-throated Jery
- Striped Kingfisher
- Stuhlmann's Starling
- Subdesert Mesite
- Sudan Golden Sparrow
- Sulphur-crested Cockatoo
- Sunbittern
- Superb Fairywren
- Superb Starling
- Surf Scoter
- Surucua Trogon
- Swahili Sparrow
- Swainson's Spurfowl
- Swallow-tailed Bee-eater
- Swallow Tanager
- Swamp Flycatcher