An Introduction to Non-Classical Logic is a 2001 mathematics textbook by philosopher and logician Graham Priest, published by Cambridge University Press.

In 2008, Priest published a substantially expanded and revised second edition under the title An Introduction to Non-Classical Logic: From If to Is.

According to American professor of philosophy Stewart Shapiro, the book is accessible to readers with a first or second undergraduate course in symbolic logic, though its optional metatheory sections require graduate-level knowledge.

Following discussion with Hájek, Priest indicated plans to revise the fuzzy logic chapter in a future edition.

Shapiro encouraged Priest to write a companion volume covering quantification in non-classical logics.