- Sabota Lark
- Sacred Kingfisher
- Sad Flycatcher
- Saddle-billed Stork
- Saffron Finch
- Sakalava Weaver
- Sand Martin
- Sanderling
- Sandhill Crane
- Sandstone Shrikethrush
- Sandwich Tern
- Sao Tome Paradise Flycatcher
- Sao Tome Prinia
- Sao Tome Thrush
- Sao Tome Weaver
- Sapphire-spangled Emerald
- Sapphire-throated Hummingbird
- Sapphire-vented Puffleg
- Sardinian Warbler
- Satin Bowerbird
- Savanna Hawk
- Savannah Sparrow
- Savi's Warbler
- Scaled Dove
- Scaly-breasted Hummingbird
- Scaly-breasted Lorikeet
- Scaly-breasted Munia
- Scaly-breasted Thrasher
- Scaly-feathered Weaver
- Scaly-throated Foliage-gleaner
- Scarlet-chested Sunbird
- Scarlet-rumped Cacique
- Scarlet-rumped Tanager
- Scarlet Macaw
- Scarlet Tanager
- Scimitar-billed Woodcreeper
- Screaming Piha
- Scrub Blackbird
- Scrub Euphonia
- Scrub Tanager
- Secretarybird
- Sedge Warbler
- Semipalmated Plover
- Sepia-capped Flycatcher
- Seychelles Black Parrot
- Seychelles Bulbul
- Seychelles Fody
- Seychelles Magpie-Robin
- Seychelles Paradise Flycatcher
- Seychelles Sunbird
- Seychelles Warbler
- Seychelles White-eye
- Shaft-tailed Whydah
- Sharp-tailed Grass Tyrant
- Shikra
- Shining Flycatcher
- Shiny Cowbird
- Shoebill
- Short-billed Dowitcher
- Short-crested Flycatcher
- Short-eared Owl
- Short-toed Rock Thrush
- Short-toed Snake Eagle
- Short-toed Treecreeper
- Shy Albatross
- Siberian Rubythroat (beicki)
- Siberian Stonechat
- Sickle-billed Vanga
- Sickle-winged Guan
- Silver-backed Butcherbird
- Silver-crowned Friarbird
- Silver-throated Tanager
- Silver Gull
- Silver Teal
- Silverbird
- Silvereye
- Singing Bush Lark
- Singing Honeyeater
- Sirkeer Malkoha
- Slate-colored Boubou
- Slate-colored Grosbeak
- Slate-throated Whitestart
- Slaty-tailed Trogon
- Slender-billed Gull
- Slender-tailed Nightjar
- Small-billed Tinamou
- Small Ground Finch
- Small Lifou White-eye
- Small Minivet
- Smew
- Smooth-billed Ani
- Snail Kite
- Snow Bunting
- Snowy Egret
- Snowy Plover
- Sociable Lapwing
- Sociable Weaver
- Social Flycatcher
- Socorro Dove
- Socotra Cormorant
- Somali Bee-eater
- Somali Bunting
- Somali Courser
- Somali Ostrich
- Sombre Greenbul
- Song Sparrow
- Sooty-capped Chlorospingus
- Sooty-headed Bulbul
- Sooty Chat
- Sooty Gull
- Sooty Tyrannulet
- Souimanga Sunbird
- South Island Oystercatcher
- South Island Robin
- South Island Takahe
- South Melanesian Cuckooshrike
- Southern Beardless Tyrannulet
- Southern Black Flycatcher
- Southern Black Korhaan
- Southern Black Tit
- Southern Cassowary
- Southern Crested Guineafowl
- Southern Grey-headed Sparrow
- Southern Ground Hornbill
- Southern House Wren
- Southern Lapwing
- Southern Masked Weaver
- Southern Red-billed Hornbill
- Southern Red-fronted Tinkerbird
- Southern Screamer
- Southern Shrikebill
- Southern White-crowned Shrike
- Southern White-faced Owl
- Southern Yellow-billed Hornbill
- Spangled Cotinga
- Spangled Drongo
- Spanish Sparrow
- Sparkling Violetear
- Speckle-fronted Weaver
- Speckled Chachalaca
- Speckled Hummingbird
- Speckled Mousebird
- Speckled Pigeon
- Spectacled Monarch
- Spectacled Thrush
- Spectacled Warbler
- Spectacled Weaver
- Speke's Weaver
- Spinifex Pigeon
- Spiny-cheeked Honeyeater
- Spix's Guan
- Splendid Fairywren
- Spot-bellied Bobwhite
- Spot-bellied Eagle-Owl
- Spot-billed Ground Tyrant
- Spot-billed Pelican
- Spot-winged Falconet
- Spot-winged Pigeon
- Spot-winged Thrush
- Spotless Starling
- Spotted Barbtail
- Spotted Catbird
- Spotted Crake
- Spotted Dove
- Spotted Flycatcher
- Spotted Nothura
- Spotted Owlet
- Spotted Palm Thrush
- Spotted Sandpiper
- Spotted Shag
- Spotted Thick-knee
- Spotted Towhee
- Spur-winged Goose
- Spur-winged Lapwing
- Squacco Heron
- Square-tailed Nightjar
- Squirrel Cuckoo
- Sri Lanka Blue Magpie
- Sri Lanka Grey Hornbill
- Sri Lanka Junglefowl
- Steller's Jay
- Steppe Eagle
- Stock Dove
- Stolid Flycatcher
- Stout Cisticola
- Straight-billed Earthcreeper
- Straight-billed Woodcreeper
- Strange-tailed Tyrant
- Straw-necked Ibis
- Streak-backed Oriole
- Streak-capped Treehunter
- Streak-eared Bulbul
- Streaked Dacnis
- Streaked Flycatcher
- Streaked Saltator
- Streaky Seedeater
- Streamer-tailed Tyrant
- Striated Heron
- Striated Pardalote (melanocephalus)
- Striated Starling
- Stripe-tailed Hummingbird
- Stripe-throated Bulbul
- Striped Cuckoo
- Striped Kingfisher
- Strong-billed Woodcreeper
- Subdesert Brush Warbler
- Subdesert Mesite
- Sulphur-bellied Flycatcher
- Sulphur-crested Cockatoo
- Summer Tanager
- Sunbittern
- Superb Fairywren
- Superb Starling
- Superciliated Wren
- Surf Scoter
- Swahili Sparrow
- Swainson's Spurfowl
- Swallow-tailed Bee-eater
- Swallow-tailed Gull
- Swallow-tailed Hummingbird
- Swallow-tailed Kite
- Swallow Tanager
- Swamp Flycatcher