Encyclopedias, Almanacs, Transcripts, and Maps
- sleepy sickness
- Slender Blindsnakes (Leptotyphlopidae)
- Slit-Faced Bats (Nycteridae)
- sloe
- Slovak
- Slovak Republic
- slow-worm
- Sludge Treatment and Disposal
- Slurry
- Small Quantity Generator
- smallest countries
- Smart, Ninian
- Smelter
- Smith, Hannah Whitall
- Smith, Morton
- Smith, Robert Angus (1817 – 1884) Scottish Chemist
- Smith, W. Robertson
- Smith, Wilfred Cantwell
- Smoky Bats (Furipteridae)
- Snakes