Encyclopedias, Almanacs, Transcripts, and Maps
- Solenodons (Solenodontidae)
- Solid Waste Incineration
- Solid Waste Landfilling
- Solid Waste Recycling and Recovery
- Solid Waste Volume Reduction
- Solidification of Hazardous Materials
- Sölle, Dorothee
- Solomon Islands Religions
- Soloveitchik, Joseph Baer
- Solovʾev, Vladimir
- solubility
- Solzhenitsyn, Alexander
- Sorberacea (Sorberaceans)
- Sorokin, Pitirim Aleksandrovich
- Sorption
- Sorskii, Nil
- Soteriology
- Soul: Ancient near Eastern Concepts
- Soul: Buddhist Concepts
- Soul: Chinese Concepts