- Sacred Kingfisher
- Saffron Finch
- Sand Martin
- Sanderling
- Sardinian Warbler
- Savannah Sparrow
- Scaly-breasted Munia
- Scaly-breasted Thrasher
- Scaly-naped Pigeon
- Scarlet-rumped Tanager
- Scarlet-rumped Tanager (costaricensis)
- Scarlet Macaw
- Scarlet Myzomela
- Scrub Greenlet
- Semipalmated Plover
- Semipalmated Sandpiper
- Shiny Cowbird
- Silver Gull
- Slaty-capped Flycatcher
- Slaty-tailed Trogon
- Smooth-billed Ani
- Snowy Egret
- Song Sparrow
- Song Thrush
- South American Tern
- Southern Fulmar
- Southern Giant Petrel
- Southern Lapwing
- Spix's Guan
- Spot-billed Toucanet
- Spotted Dove
- Spotted Sandpiper
- Spur-winged Lapwing
- Squirrel Cuckoo
- Steller's Jay
- Streak-eared Bulbul
- Striated Heron
- Striped Woodpecker
- Sulphur-bellied Flycatcher
- Sunda Zebra Finch
- Swan Goose