Quebracho is one of the common names, in Spanish, of at least three similar species of trees that grow in the Gran Chaco region of South America:

• Schinopsis lorentzii (quebracho colorado santiagueño), of the family Anacardiaceae;
• Schinopsis balansae (quebracho colorado chaqueño), of the same family;
• Aspidosperma quebracho-blanco ("white quebracho"), of the family Apocynaceae.

These species provide tannin and a very hard, durable timber. Quebracho is sometimes used as a commercial name for the tannin derived from the trees, or their timber. The etymology of the name appears to be Spanish quiebrahacha, "axe-breaker".

The tannic acid, in the form of alkalized salts, was extensively used as a deflocculant in drilling muds in 1940s-1950s, until it was replaced with lignosulfonates. Its red color gave the mixture the name red mud.