T38 or T-38 may refer to:

• Allison T38, an American turboprop aircraft engine
• Northrop T-38 Talon, an American jet trainer aircraft
• Slingsby T.38 Grasshopper, a British training glider

• T38 (classification), a disability sport classification
• T.38, an ITU-T recommendation
• Cooper T38, a British sports car
• T-38 tank, a Soviet light tank
• TACAM T-38, a Romanian tank destroyer