THB

THB may refer to:

Tetrahydrobiopterin, a chemical
Thai baht, the currency of Thailand (ISO 4217 code: THB)
THB (comics), and its eponymous character Tri-Hydro Bi-Oxygenate
The Holy Bible
The Hydra Bay, a piracy site
Thomas Hart Benton (painter) (1889–1975), American painter and muralist 
Thomas Hart Benton (senator) (1782–1858), American politician from Missouri and great uncle of the painter
Three Horses Beer, a beer made in Madagascar
Too Hard Basket
Toronto, Hamilton and Buffalo Railway