Th or TH may stand for:
- the symbol for the chemical element thorium (Th)
- the 29th letter of the Albanian alphabet, see th (letter)
- the symbol of thoracic vertebrae (Th1-Th12)
- a digraph used
- in English to identify the sounds /θ/ and /ð/ (IPA).
- in some Celtic languages to refer to the product of lenition of t.
- Thailand (ISO country code)