Complementarity may refer to:
Physical sciences and mathematics Complementarity (molecular biology), a property of nucleic acid molecules in molecular biology Complementarity (physics), the principle that objects have complementary properties which cannot all be observed or measured simultaneously Complementarity theory, a type of mathematical optimization problem Quark–lepton complementarity, a possible fundamental symmetry between quarks and leptons
Society and law Complementarianism, a theological view that men and women have different but complementary roles Complementary good, a good for which demand is increased when the price of another good is decreased An element of interpersonal compatibility in social psychology The principle that the International Criminal Court is a court of last resort
See also Complementarity-determining region, part of the variable chains in immunoglobulins Complementary angles, in geometry Self-complementary graph, in graph theory Yin and yang, complementary relation between apparent opposites in Chinese philosophy Complimentary (disambiguation) Complement (disambiguation)