- Sabine's Gull
- Sabine's Spinetail
- Sabota Lark
- Sacred Kingfisher
- Saddle-billed Stork
- Saffron Finch
- Saffron Siskin
- Sahel Bush Sparrow
- Sahel Paradise Whydah
- Saker Falcon
- Sakhalin Leaf Warbler
- Salvadori's Fig Parrot
- Salvadori's Nightjar
- Salvadori's Teal
- Salvin's Albatross
- Samoan Fantail
- Samoan Flycatcher
- Samoan Starling
- Samoan Triller
- Samoan Whistler
- Sand-colored Nighthawk
- Sand Martin
- Sanderling
- Sandhill Crane
- Sandwich Tern
- Sanford's Sea Eagle
- Sao Tome Fiscal
- Sao Tome Green Pigeon
- Sao Tome Ibis
- Sao Tome Oriole
- Sao Tome Paradise Flycatcher
- Sao Tome Prinia
- Sao Tome Scops Owl
- Sao Tome Spinetail
- Sao Tome Thrush
- Sao Tome Weaver
- Sao Tome White-eye
- Sapphire-spangled Emerald
- Sapphire-vented Puffleg
- Sardinian Warbler
- Sarus Crane
- Saturnine Antshrike
- Savanna Hawk
- Savannah Sparrow
- Say's Phoebe
- Sayaca Tanager
- Scale-crested Pygmy Tyrant
- Scale-throated Earthcreeper
- Scale-throated Hermit
- Scaled Antbird
- Scaled Antpitta
- Scaled Dove
- Scaled Pigeon
- Scaled Quail
- Scaly-breasted Cupwing
- Scaly-breasted Munia
- Scaly-crowned Honeyeater
- Scaly-feathered Weaver
- Scaly-throated Foliage-gleaner
- Scaly-throated Honeyguide
- Scaly Chatterer
- Scaly Spurfowl
- Scarce Swift
- Scarlet-backed Woodpecker
- Scarlet-breasted Flowerpecker
- Scarlet-chested Sunbird
- Scarlet-crowned Barbet
- Scarlet-hooded Barbet
- Scarlet-horned Manakin
- Scarlet Flycatcher
- Scarlet Ibis
- Scarlet Robin
- Scissor-tailed Flycatcher
- Scissor-tailed Kite
- Sclater's Tyrannulet
- Sclater's Whistler
- Scopoli's Shearwater
- Scott's Oriole
- Scripps's Murrelet
- Scrub Blackbird
- Scrub Tanager
- Seaside Sparrow
- Secretarybird
- Sedge Warbler
- Semicollared Flycatcher
- Semipalmated Plover
- Semipalmated Sandpiper
- Senegal Coucal
- Senegal Eremomela
- Senegal Parrot
- Senegal Thick-knee
- Seven-colored Tanager
- Shaft-tailed Whydah
- Sharp-shinned Hawk
- Sharp-tailed Sandpiper
- Sharp-tailed Starling
- Sharpbill
- Sharpe's Starling
- Shelley's Greenbul
- Shelley's Oliveback
- Shelley's Sparrow
- Shelley's Starling
- Shikra
- Shining-blue Kingfisher
- Shining-green Hummingbird
- Shining Bronze Cuckoo
- Shining Drongo
- Shining Flycatcher
- Shining Sunbeam
- Shining Sunbird
- Shore Dotterel
- Short-bearded Honeyeater
- Short-billed Dowitcher
- Short-crested Flycatcher
- Short-eared Owl
- Short-legged Ground Roller
- Short-tailed Antthrush
- Short-tailed Parrot
- Short-tailed Starling
- Short-tailed Swift
- Short-tailed Woodstar
- Short-toed Rock Thrush
- Short-toed Snake Eagle
- Short-toed Treecreeper
- Shy Albatross
- Siamese Fireback
- Siberian Accentor
- Siberian Blue Robin
- Siberian Jay
- Siberian Rubythroat
- Siberian Stonechat
- Siberian Thrush
- Sichuan Leaf Warbler
- Silver-backed Needletail
- Silver-backed Tanager
- Silver-breasted Broadbill
- Silver-capped Fruit Dove
- Silver-eared Honeyeater
- Silver-throated Tanager
- Silver Gull
- Silver Pheasant
- Silverbird
- Silvereye
- Silvery-cheeked Antshrike
- Silvery-cheeked Hornbill
- Silvery-flanked Antwren
- Simple Greenbul
- Sincora Antwren
- Sind Sparrow
- Singing Cisticola
- Singing Honeyeater
- Singing Starling
- Sjöstedt's Barred Owlet
- Slate-colored Boubou
- Slate-colored Grosbeak
- Slate-throated Whitestart
- Slaty-backed Chat-Tyrant
- Slaty-backed Gull
- Slaty-blue Flycatcher
- Slaty-breasted Rail
- Slaty-capped Flycatcher
- Slaty-headed Parakeet
- Slaty Brushfinch
- Slaty Gnateater
- Slaty Monarch
- Slaty Robin
- Slaty Spinetail
- Slender-billed Greenbul
- Slender-billed Gull
- Slender-billed Parakeet
- Slender-billed Weaver
- Slender-tailed Nightjar
- Slender Antbird
- Small Lifou White-eye
- Small Minivet
- Smew
- Smith's Longspur
- Smoke-colored Pewee
- Smoky-fronted Tody-Flycatcher
- Smoky Bush Tyrant
- Smoky Robin
- Smooth-billed Ani
- Snail Kite
- Snow Bunting
- Snow Goose
- Snow Mountain Quail
- Snow Pigeon
- Snowy-browed Flycatcher
- Snowy-crowned Robin-Chat
- Snowy-throated Kingbird
- Snowy Egret
- Snowy Owl
- Snowy Sheathbill
- Sociable Lapwing
- Sociable Weaver
- Sokoke Pipit
- Sokoke Scops Owl
- Solitary Sandpiper
- Solitary Tinamou
- Solomons Boobook
- Solomons Cockatoo
- Solomons Cuckooshrike
- Solomons Frogmouth
- Solomons White-eye
- Somali Bunting
- Somali Courser
- Somali Fiscal
- Somali Ostrich
- Somali Short-toed Lark
- Sombre Greenbul
- Sombre Hummingbird
- Song Parrot
- Song Sparrow
- Song Thrush
- Sooretama Slaty Antshrike
- Sooty-headed Bulbul
- Sooty-headed Tyrannulet
- Sooty Antbird
- Sooty Babbler
- Sooty Flycatcher
- Sooty Fox Sparrow
- Sooty Gull
- Sooty Honeyeater
- Sooty Myzomela
- Sooty Oystercatcher
- Sooty Shearwater
- Sooty Tern
- South African Shelduck
- South American Snipe
- South Georgia Diving Petrel
- South Island Robin
- South Island Saddleback
- South Island Takahe
- South Melanesian Cuckooshrike
- Southern Beardless Tyrannulet
- Southern Black Flycatcher
- Southern Black Tit
- Southern Brown Kiwi
- Southern Chestnut-tailed Antbird
- Southern Crested Caracara
- Southern Double-collared Sunbird
- Southern Emu-wren
- Southern Fiscal
- Southern Grey-headed Sparrow
- Southern Ground Hornbill
- Southern Lapwing
- Southern Masked Weaver
- Southern Mealy Amazon
- Southern Red-billed Hornbill
- Southern Red Bishop
- Southern Rough-winged Swallow
- Southern Royal Albatross
- Southern Whiteface
- Southern Yellow-billed Hornbill
- Spangled Coquette
- Spangled Cotinga
- Spangled Honeyeater
- Spanish Sparrow
- Sparkling Violetear
- Speckle-fronted Weaver
- Speckled Chachalaca
- Speckled Hummingbird
- Speckled Mousebird
- Speckled Pigeon
- Speckled Spinetail
- Speckled Tanager
- Speckled Tinkerbird
- Spectacled Bulbul
- Spectacled Eider
- Spectacled Guillemot
- Spectacled Parrotlet
- Spectacled Tyrant
- Spectacled Warbler
- Spectacled Weaver
- Spectacled Whitestart
- Speke's Weaver
- Spike-heeled Lark
- Spiny-cheeked Honeyeater
- Spix's Guan
- Spix's Spinetail
- Splendid Astrapia
- Splendid Starling
- Splendid Sunbird
- Spoon-billed Sandpiper
- Spot-billed Pelican
- Spot-billed Toucanet
- Spot-breasted Heleia
- Spot-breasted Lapwing
- Spot-flanked Barbet
- Spot-flanked Gallinule
- Spot-necked Babbler
- Spot-winged Falconet
- Spot-winged Monarch
- Spotless Crake
- Spotless Starling
- Spotted Berrypecker
- Spotted Bush Warbler
- Spotted Crake
- Spotted Crocias
- Spotted Dove
- Spotted Eagle-Owl
- Spotted Flycatcher
- Spotted Forktail
- Spotted Greenbul
- Spotted Honeyeater
- Spotted Honeyguide
- Spotted Kestrel
- Spotted Nutcracker
- Spotted Owl
- Spotted Owlet
- Spotted Palm Thrush
- Spotted Pardalote
- Spotted Piculet
- Spotted Puffbird
- Spotted Redshank
- Spotted Sandpiper
- Spotted Shag
- Spotted Thick-knee
- Spotted Tody-Flycatcher
- Spotted Towhee
- Spur-winged Goose
- Spur-winged Lapwing
- Squacco Heron
- Square-tailed Drongo-Cuckoo
- Squirrel Cuckoo
- Standard-winged Nightjar
- Steel-blue Flycatcher
- Steere's Liocichla
- Stejneger's Stonechat
- Steller's Eider
- Steller's Jay
- Steller's Sea Eagle
- Steppe Eagle
- Stilt Sandpiper
- Stitchbird
- Stock Dove
- Stone Partridge
- Stork-billed Kingfisher
- Stout-billed Cinclodes
- Stout-billed Cuckooshrike
- Stout Cisticola
- Straight-billed Woodcreeper
- Straw-necked Ibis
- Straw-tailed Whydah
- Streak-breasted Honeyeater
- Streak-capped Treehunter
- Streak-eared Bulbul
- Streak-headed Antbird
- Streak-headed Honeyeater
- Streak-headed Woodcreeper
- Streak-throated Bush Tyrant
- Streak-throated Canastero
- Streak-throated Woodpecker
- Streaked Fantail
- Streaked Flycatcher
- Streaked Laughingthrush
- Streaked Rosefinch
- Streaked Scrub Warbler
- Streaked Spiderhunter
- Streaked Tuftedcheek
- Streaked Weaver
- Streaked Xenops
- Streaky Seedeater
- Stresemann's Bushcrow
- Striated Antbird
- Striated Babbler
- Striated Fieldwren
- Striated Grassbird
- Striated Heron
- Striated Laughingthrush
- Striated Softtail
- Striated Starling
- Striolated Bunting
- Striolated Manakin
- Stripe-backed Wren
- Stripe-breasted Woodpecker
- Stripe-chested Antwren
- Stripe-faced Greenbul
- Stripe-headed Antpitta
- Stripe-necked Tody-Tyrant
- Stripe-tailed Yellow Finch
- Stripe-throated Bulbul
- Stripe-throated Hermit
- Striped Cuckoo
- Striped Kingfisher
- Striped Pipit
- Strong-billed Honeyeater
- Strong-billed Woodcreeper
- Stubble Quail
- Stuhlmann's Starling
- Styan's Bulbul
- Styan's Grasshopper Warbler
- Stygian Owl
- Subalpine Warbler
- Subdesert Mesite
- Sudan Golden Sparrow
- Sulphur-bellied Warbler
- Sulphur-breasted Myzomela
- Sulphur-crested Cockatoo
- Sulphur-rumped Myiobius
- Sultan Tit
- Sumba Boobook
- Sumba Brown Flycatcher
- Sumba Buttonquail
- Sumba Green Pigeon
- Sumba Hornbill
- Sumba Myzomela
- Summer Tanager
- Sun Lark
- Sunbittern
- Sunda Bulbul
- Sunda Bush Warbler
- Sunda Cuckoo
- Sunda Cuckooshrike
- Sunda Forktail
- Sunda Minivet
- Sunda Pygmy Woodpecker
- Sunda Robin
- Sunda Teal
- Sunda Warbler
- Sungrebe
- Superb Fairywren
- Superb Fruit Dove
- Superb Parrot
- Superb Starling
- Superb Sunbird
- Superciliaried Hemispingus
- Superciliated Wren
- Surf Scoter
- Surfbird
- Swahili Sparrow
- Swainson's Hawk
- Swainson's Sparrow
- Swainson's Spurfowl
- Swainson's Thrush
- Swallow-tailed Bee-eater
- Swallow-tailed Hummingbird
- Swallow-tailed Kite
- Swallow-winged Puffbird
- Swallow Tanager
- Swamp Boubou
- Swamp Flycatcher
- Swamp Francolin
- Swamp Harrier
- Swinhoe's Minivet
- Swinhoe's Pheasant
- Sword-billed Hummingbird
- Sykes's Lark
- Sykes's Nightjar