4T

4T or 4-T may refer to:

Biology and chemistry

 * 4-T-TRIS; see Thiotrisescaline
 * 4-t-butylpyrocatechol; see 4-tert-Butylcatechol
 * 4T-MMDA-2; see MMDA

Locomotives

 * 4T class of locomotive
 * LMS Stanier 2-6-4T (disambiguation)
 * LMS 3-Cylindered Stanier 2-6-4T
 * LMS Fairburn 2-6-4T
 * LMS Fowler 2-6-4T
 * Bristol and Exeter Railway 4-2-4T locomotives
 * LMS/BR Class 4 2-6-4T locomotives
 * BR Standard Class 4 2-6-4T
 * LMS 2-Cylindered Stanier 2-6-4T
 * L&YR Hughes 4-6-4T
 * LMS Stanier Class 2 0-4-4T
 * Highland Railway Drummond 0-6-4T Class
 * Highland Railway Drummond 0-4-4T Class
 * 0-8-4T
 * 2-6-4T; see 2-6-4
 * 0-4-4T; see 0-4-4
 * 4-6-4T; see 4-6-4
 * 0-6-4T; see 0-6-4
 * 2-8-4T; see 2-8-4
 * 2-2-4T; see 2-2-4
 * 2-4-4T; see 2-4-4

Other

 * 4T-GTE, a model of Toyota T engine
 * 4T, a model of LWD Szpak, a Polish utility aircraft
 * Piaggio Zip 4T, an urban scooter
 * 4T – Vietnam Youth Education Support Center
 * 4T, the production code for the 1977 Doctor Who serial The Invisible Enemy
 * Fourth Transformation, 2018 campaign promise by Mexico's president to do away with abuses that plagued that nation.