Theory, Stable theory, Set theory, Superstring theory, Theory of computation, Critical theory, Grounded theory, Theory (mathematical logic), Computability theory, Theory X and Theory Y, M-theory, Theory-theory, String theory, Type theory, Number theory, Scientific theory, Game theory, Model theory, Decision theory, Twistor theory, Theory of everything, Gauge theory, Information theory, Götaland theory, Probability theory, Naive set theory, Systems theory, Economic Theory, Intuitionistic type theory, Negotiation theory, Group theory, Unified field theory, Germ theory denialism, Fringe theory, Queer theory, Dynamical systems theory, Organizational theory, Descriptivist theory of names, Theory of relativity, Communication theory, International relations theory

Nordström's theory of gravitation, Molecular orbital theory, Practice theory, Circumscription theory, Morse–Kelley set theory, Complexity theory and organizations, Theory of mind, Cannon–Bard theory, C-K theory, Social theory, Interpolation theory, Lie theory, Scalar–tensor theory, Drive theory, Outline of critical theory, Labeling theory, Cell theory, Emission theory (relativity), Theory (clothing retailer), Combinatorial game theory, Coding theory, Psychoanalytic theory, Inter-universal Teichmüller theory, Strain theory (sociology), Seiberg–Witten theory, F-theory, Evolution as fact and theory, Quare theory, Vapnik–Chervonenkis theory, BCS theory, Statistical theory, Continuity theory, Caloric theory, Conspiracy theory, Lawvere theory, Labor theory of value, Quantum field theory, Equity theory, Literary theory, Causal theory of reference, Theory of Colours, Type II string theory, Theory of art, Path–goal theory, Twisted K-theory, Valence bond theory, Sociological theory, Germ theory of disease, Zermelo set theory, Temporal theory (hearing)

Theory, Stable theory, Set theory, Superstring theory, Theory of computation, Critical theory, Grounded theory, Theory (mathematical logic), Computability theory, Theory X and Theory Y, M-theory, Theory-theory, String theory, Type theory, Number theory, Scientific theory, Game theory, Model theory, Decision theory, Twistor theory, Theory of everything, Gauge theory, Information theory, Götaland theory, Probability theory, Naive set theory, Systems theory, Economic Theory, Intuitionistic type theory, Negotiation theory, Group theory, Unified field theory, Germ theory denialism, Fringe theory, Queer theory, Dynamical systems theory, Organizational theory, Descriptivist theory of names, Theory of relativity, Communication theory, International relations theory, Nordström's theory of gravitation, Molecular orbital theory, Practice theory, Circumscription theory, Morse–Kelley set theory, Complexity theory and organizations, Theory of mind, Cannon–Bard theory, C-K theory, Social theory, Interpolation theory, Lie theory, Scalar–tensor theory, Drive theory, Outline of critical theory, Labeling theory, Cell theory, Emission theory (relativity), Theory (clothing retailer), Combinatorial game theory, Coding theory, Psychoanalytic theory, Inter-universal Teichmüller theory, Strain theory (sociology), Seiberg–Witten theory, F-theory, Evolution as fact and theory, Quare theory, Vapnik–Chervonenkis theory, BCS theory, Statistical theory, Continuity theory, Caloric theory, Conspiracy theory, Lawvere theory, Labor theory of value, Quantum field theory, Equity theory, Literary theory, Causal theory of reference, Theory of Colours, Type II string theory, Theory of art, Path–goal theory, Twisted K-theory, Valence bond theory, Sociological theory, Germ theory of disease, Zermelo set theory, Temporal theory (hearing), Regality theory, Actor–network theory, Pattern theory, Heterotic string theory, Two-factor theory, Contract theory, Chern–Simons theory, Introduction to M-theory, Bisexual theory, Theory of a Deadman, Matrix string theory, Graph theory, Yang–Mills theory, Miasma theory, Dual-coding theory, Set theory (music), Transformational theory, Development theory, Transition state theory, Representation theory, A Theory of Justice, Dependency theory, Perturbation theory, Subjective theory of value, Singularity theory, Liouville field theory, Control theory, Bow-wow theory, Potential theory, K-theory, Algorithmic learning theory, Power transition theory, Ring theory, Constructive set theory, Theories of humor, Theory of forms, Ginzburg–Landau theory, Journal of Combinatorial Theory, KK-theory, ∞-Chern–Weil theory, A¹ homotopy theory, Grand Unified Theory, Optimality theory, Brans–Dicke theory, Supersymmetric theory of stochastic dynamics, Structuration theory, Dempster–Shafer theory, World-systems theory, Automata theory, Postdevelopment theory, Pecking order theory, Kaluza–Klein theory, Free-radical theory of aging, Journal of Approximation Theory, Film theory, Kripke–Platek set theory, Genus theory, Elastica theory, Einstein–Cartan theory, Normalization process theory