Encyclopedias, Almanacs, Transcripts, and Maps
- Siberian Mythology
- Sicilian Fasci
- Sicily, Invasion of
- Sickle-Cell Disease
- Side Arms, Standard Infantry
- Sidney Kidman
- Sidney Robert Nolan
- Sidney, Philip (1554–1586)
- Sidonie Gabrielle Colette
- Siemens, Werner von
- Sieur d'Iberville
- Sieur de Bienville
- Sieur de La Salle
- Sieur de la Verendrye
- Sieyès, Emmanuel-Joseph
- Sigeberht
- Sigismund II Augustus (Poland, Lithuania) (1520–1572; ruled 1530–1572)
- Sign Manual
- Signers
- Sigurd, jarl of Orkney