A. Thomas Tymoczko (1943–1996) was a philosopher specializing in logic and the philosophy of mathematics. He taught at Smith College in Northampton, Massachusetts from 1971 until his untimely death.

His publications include New Directions in the Philosophy of Mathematics, an edited collection of essays for which he wrote individual introductions, and Sweet Reason: A Field Guide to Modern Logic, co-authored by Jim Henle. In addition, he published a number of philosophical articles, such as "The Four-Color Problem and its Philosophical Significance", which argues that the increasing use of computers is changing the nature of mathematical proof.

He can be considered a member of the quasi-empiricist or fallibilist school in philosophy of mathematics inspired by the work of Imre Lakatos. Philip Kitcher dubbed this school the "maverick" tradition in the philosophy of mathematics. (Paul Ernest)