- Sacred Kingfisher
- Salvin's Albatross
- San Cristobal Mockingbird
- Sanderling
- Sardinian Warbler
- Scaled Fruiteater
- Scarlet-bellied Mountain Tanager
- Scarlet-rumped Tanager
- Scarlet-thighed Dacnis
- Scarlet Macaw
- Semipalmated Plover
- Shining Sunbeam
- Short-crested Flycatcher
- Short-toed Snake Eagle
- Short-toed Treecreeper
- Sickle-winged Guan
- Silver-beaked Tanager
- Silver Gull (scopulinus)
- Silvereye
- Slate-colored Hawk
- Slate-throated Whitestart
- Slaty-capped Flycatcher
- Slaty Flowerpiercer
- Smoke-colored Pewee
- Smoky-brown Woodpecker
- Smooth-billed Ani
- Social Flycatcher
- Song Thrush
- Sooty-capped Chlorospingus
- South Island Robin
- South Island Takahe
- Southern Brown Kiwi
- Southern House Wren
- Southern Rough-winged Swallow
- Spangled Coquette
- Sparkling Violetear
- Speckled Chachalaca
- Spectacled Warbler
- Spectacled Whitestart
- Spix's Guan
- Spotted Dove
- Spotted Flycatcher
- Spotted Redshank
- Spotted Sandpiper
- Spotted Shag
- Spotted Woodcreeper
- Squirrel Cuckoo
- Stitchbird
- Stock Dove
- Stout-billed Cinclodes
- Streak-headed Woodcreeper
- Striated Heron
- Striped Treehunter
- Strong-billed Woodcreeper
- Sulphur-rumped Myiobius
- Sungrebe
- Swallow-tailed Gull
- Swallow-tailed Kite
- Swallow-winged Puffbird
- Swamp Harrier