- Tallinn University of Technology
- Tan Tao University
- Tarbiat Modares University [Tehran]
- Taxonomia International Foundation
- Teagasc Agriculture and Food Development Authority
- Teagasc—Agriculture and Food Development Authority, Kinsealy Research Centre
- Teagasc, Environment Research Centre, Wexford, Ireland
- Teagasc Food Research Centre [Fermoy, Ireland]
- Teagasc - The Agriculture and Food Development Authority
- Technical University of Lisbon
- Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig]
- Technische Universität Dresden = Dresden University of Technology
- Technische Universität Munchen - Technical University Munich - Université Technique de Munich
- Technological Educational Institute of Kavala
- Technological Education Institute of Lamia
- Tembotov Institute of Ecology of Mountain Territories, Russian Academy of Sciences
- TerraQ Pte Ltd
- Terrena
- Terres Inovia
- Texas A and M AgriLife Research
- Thaksin University
- Thaksin University International College (Thaksin University)
- the Climate Data Factory
- The James Hutton Institute
- The Morton Arboretum
- The Nature Conservancy
- The University of Queensland
- The University of Sydney
- The University of the South Pacific [Suva, Fidji]
- The University of the West Indies
- Thuenen-Institute of Biodiversity
- Thuenen-Institute of Organic Farming
- Tochigi Prefectural Museum
- Trier University
- Trinity College Dublin
- Turkish Atomic Energy Authority