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

Organizational theory, Practice theory, Theory of relativity, International relations theory, Morse–Kelley set theory, Theory of mind, Scalar–tensor theory, Complexity theory and organizations, C-K theory, Emission theory (relativity), Theory (clothing retailer), Drive theory, Labeling theory, Interpolation theory, Cannon–Bard theory, Social theory, Outline of critical theory, Combinatorial game theory, Vapnik–Chervonenkis theory, Psychoanalytic theory, Strain theory (sociology), BCS theory, Quare theory, Continuity theory, Seiberg–Witten theory, Lie theory, F-theory, Cell theory, Coding theory, Caloric theory, Inter-universal Teichmüller theory, Causal theory of reference, Quantum field theory, Type II string theory, Labor theory of value, Germ theory of disease, Statistical theory, Theory of art, Evolution as fact and theory, Twisted K-theory, Theory of Colours, Lawvere theory, Actor–network theory, Sociological theory, Valence bond theory, Conspiracy theory, Theory of a Deadman, Bisexual theory, Yang–Mills theory, Two-factor theory

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