Encyclopedias, Almanacs, Transcripts, and Maps
- Tennyson, Alfred, 1st Baron
- Tenrecs (Tenrecidae)
- Tenrikyō
- tequila
- Teresa of Ávila
- Territorial Sea
- Teshub
- Tesla, Nikola (1856–1943)
- Test Ban Treaty
- Testudines (Turtles and Tortoises)
- Tetraethyl Lead
- Tetraodontiformes (Pufferfishes, Triggerfishes, and Relatives)
- Teutonic mythology
- Thai Religion
- Thaliacea (Salps)
- The Bahamas
- The Global 2000 Report
- The Netherlands
- The Philippines
- The Ungulates (Hoofed Mammals)