Heterodox economics is any economic thought or theory that contrasts with orthodox schools of economic thought, or that may be beyond neoclassical economics. These include institutional, evolutionary, feminist, social, post-Keynesian (not to be confused with New Keynesian), ecological, Austrian, complexity, Marxian, socialist, and anarchist economics.

Economics may be called orthodox or conventional economics by its critics. Alternatively, mainstream economics deals with the "rationality–individualism–equilibrium nexus" and heterodox economics is more "radical" in dealing with the "institutions–history–social structure nexus".

A 2008 review documented several prominent groups of heterodox economists since at least the 1990s as working together with a resulting increase in coherence across different constituents. Along these lines, the International Confederation of Associations for Pluralism in Economics (ICAPE) does not define "heterodox economics" and has avoided defining its scope. ICAPE defines its mission as "promoting pluralism in economics."

In defining a common ground in the "critical commentary", one writer described fellow heterodox economists as trying to do three things: (1) identify shared ideas that generate a pattern of heterodox critique across topics and chapters of introductory macro texts; (2) give special attention to ideas that link methodological differences to policy differences; and (3) characterize the common ground in ways that permit distinct paradigms to develop common differences with textbook economics in different ways.

One study suggests four key factors as important to the study of economics by self-identified heterodox economists: history, natural systems, uncertainty, and power.