Encyclopedias, Almanacs, Transcripts, and Maps
- Thealogy
- Thecla
- Thecostraca (Cirripedes and Relatives)
- Theodore of Studios
- Theodoret of Cyrrhus
- Theology: Christian Theology
- Theology: Comparative Theology
- Theravāda
- Thérèse of Lisieux, Saint
- Therianthropism
- Thermal Energy
- Thermal Plume
- Thermal Stratification (Water)
- Thermosbaenacea (Thermosbaenaceans)
- Thermosetting Polymers
- Thesmophoria
- Thiasoi
- Thick-Knees (Burhinidae)
- Third World Pollution
- Thomas À Kempis