Functionalism may refer to:

• Functionalism (architecture), the principle that architects should design a building based on the purpose of that building
• Functionalism in international relations, a theory that arose during the inter-War period
• Functional linguistics, a theoretical approach to the study of language
• Functionalism (philosophy of mind), a theory of the mind in contemporary philosophy
• Functionalism versus intentionalism, a historiographical debate about the origins of the Holocaust
• Structural functionalism, a theoretical tradition within sociology and anthropology
• Biological functionalism, an anthropological paradigm

• Danish functional linguistics
• Functional (disambiguation)
• Functional psychology
• Neofunctionalism