- Sacred Kingfisher
- Saddle-billed Stork
- Saffron Finch
- Sage Thrasher
- Sahul Sunbird
- Sakalava Weaver
- Salvin's Albatross
- Sanderling
- Sandhill Crane
- Sandstone Shrikethrush
- Sarus Crane
- Satin Bowerbird
- Satin Flycatcher
- Savanna Hawk
- Say's Phoebe
- Scaly-breasted Lorikeet
- Scaly-breasted Munia
- Scarlet Ibis
- Scarlet Macaw
- Scarlet Myzomela
- Screaming Piha
- Secretarybird
- Semipalmated Plover
- Semipalmated Sandpiper
- Seychelles Black Parrot
- Seychelles Blue Pigeon
- Seychelles Bulbul
- Seychelles Fody
- Seychelles Magpie-Robin
- Seychelles Paradise Flycatcher
- Seychelles Sunbird
- Seychelles Warbler
- Sharp-tailed Sandpiper
- Shining Bronze Cuckoo
- Shining Flycatcher
- Shiny Cowbird
- Short-billed Dowitcher
- Short-crested Flycatcher
- Short-tailed Hawk
- Short-tailed Swift
- Short-toed Snake Eagle
- Siberian Sand Plover
- Sickle-billed Vanga
- Silver-beaked Tanager
- Silver-crowned Friarbird
- Silver Gull
- Silver Gull (scopulinus)
- Silverbird
- Silvereye
- Silvery-cheeked Hornbill
- Singing Bush Lark
- Singing Honeyeater
- Slate-colored Boubou
- Slate-colored Grosbeak
- Slate-throated Whitestart
- Slender-footed Tyrannulet
- Smooth-billed Ani
- Snail Kite
- Snow Bunting
- Snow Goose
- Snowy Albatross
- Snowy Egret
- Social Flycatcher
- Solitary Sandpiper
- Sombre Greenbul
- Song Sparrow
- Song Thrush
- Sooty Barbthroat
- Sooty Oystercatcher
- Sooty Tern
- Souimanga Sunbird
- South African Shelduck
- South Island Oystercatcher
- South Island Robin
- South Island Takahe
- Southern Beardless Tyrannulet
- Southern Boubou
- Southern Cassowary
- Southern Double-collared Sunbird
- Southern Fiscal
- Southern Fiscal (marwitzi)
- Southern Giant Petrel
- Southern Ground Hornbill
- Southern Martin
- Southern Masked Weaver
- Southern Mouse-colored Tyrannulet
- Southern Red Bishop
- Southern Rough-winged Swallow
- Southern White-fringed Antwren
- Southern Whiteface
- Spangled Drongo
- Speckle-fronted Weaver
- Speckled Mousebird
- Speckled Pigeon
- Spectacled Monarch
- Spectacled Thrush
- Spectacled Weaver
- Spinifex Pigeon
- Spiny-cheeked Honeyeater
- Splendid Fairywren
- Spot-backed Antbird
- Spot-billed Pelican
- Spot-breasted Woodpecker
- Spotted Dove
- Spotted Eagle-Owl
- Spotted Harrier
- Spotted Owlet
- Spotted Pardalote
- Spotted Puffbird
- Spotted Quail-thrush
- Spotted Sandpiper
- Spotted Shag
- Spotted Tanager
- Spotted Thick-knee
- Spotted Tody-Flycatcher
- Spotted Towhee
- Spruce Grouse
- Spur-winged Goose
- Spur-winged Lapwing
- Squacco Heron
- Squirrel Cuckoo
- Star Finch
- Steller's Jay
- Stitchbird
- Straight-billed Hermit
- Straight-billed Woodcreeper
- Straw-necked Ibis
- Streak-throated Woodpecker
- Streaked Flycatcher
- Streaky-headed Seedeater
- Striated Heron
- Striated Pardalote (substriatus)
- Striated Starling
- Striped Cuckoo
- Striped Owl
- Strong-billed Honeyeater
- Subdesert Mesite
- Sulphur-crested Cockatoo
- Sunda Zebra Finch
- Superb Fairywren
- Superb Fruit Dove
- Superb Lyrebird
- Superb Starling
- Swainson's Hawk
- Swallow-tailed Kite
- Swallow-winged Puffbird
- Swamp Harrier