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.

See also

• The Four T's (disambiguation)
• T4 (disambiguation)
• TTTT