S
- S–cobordism theorem (differential topology)
- Saccheri–Legendre theorem (absolute geometry)
- Sahlqvist correspondence theorem (modal logic)
- Saint-Venant's theorem (physics)
- Sard's theorem (differential geometry)
- Sarkovskii's theorem (dynamical systems)
- Savitch's theorem (computational complexity theory)
- Sazonov's theorem (functional analysis)
- Schaefer's dichotomy theorem (computational complexity theory)
- Schauder fixed point theorem (functional analysis)
- Schilder's theorem (stochastic processes)
- Schnyder's theorem (graph theory)
- Schreier refinement theorem (group theory)
- Schröder–Bernstein theorems for operator algebras (operator algebras)
- Schroeder–Bernstein theorem for measurable spaces (measure theory)
- Schur's lemma (representation theory)
- Schur's theorem (Ramsey theory)
- Schur–Zassenhaus theorem (group theory)
- Schwartz kernel theorem (generalized functions)
- Schwartz–Zippel theorem (polynomials)
- Schwarz–Ahlfors–Pick theorem (differential geometry)
- Schwenk's theorem (graph theory)
- Scott core theorem (3-manifolds)
- Seifert–van Kampen theorem (algebraic topology)
- Separating axis theorem (convex geometry)
- Shannon–Hartley theorem (information theory)
- Shannon's expansion theorem (Boolean algebra)
- Shannon's source coding theorem (information theory)
- Shell theorem (physics)
- Shirshov–Witt theorem (Lie algebra)
- Shannon's theorem (information theory)
- Shift theorem (differential operators)
- Siegel–Walfisz theorem (analytic number theory)
- Silverman–Toeplitz theorem (mathematical analysis)
- Simplicial approximation theorem (algebraic topology)
- Sinkhorn's theorem (matrix theory)
- Sion's minimax theorem (game theory)
- Sipser–Lautemann theorem (probabilistic complexity theory) (structural complexity theory)
- Siu's semicontinuity theorem (complex analysis)
- Six circles theorem (circles)
- Six exponentials theorem (transcendence theory)
- Sklar's theorem (statistics)
- Skoda–El Mir theorem (complex geometry)
- Skolem–Mahler–Lech theorem (number theory)
- Skolem–Noether theorem (simple algebras)
- Skorokhod's embedding theorem (statistics)
- Skorokhod's representation theorem (statistics)
- Śleszyński–Pringsheim theorem (continued fraction)
- Slutsky's theorem (probability theory)
- Smn theorem (recursion theory, computer science)
- Sobolev embedding theorem (mathematical analysis)
- Sokhatsky–Weierstrass theorem (complex analysis)
- Sonnenschein–Mantel–Debreu Theorem (economics)
- Sophie Germain's theorem (number theory)
- Soul theorem (Riemannian geometry)
- Soundness theorem (mathematical logic)
- Space hierarchy theorem (computational complexity theory)
- Specht's theorem (matrix theory)
- Spectral theorem (functional analysis)
- Speedup theorem (computational complexity theory)
- Sperner's theorem (combinatorics)
- Sphere theorem (Riemannian geometry)
- Spin-statistics theorem (physics)
- Sprague–Grundy theorem (combinatorial game theory)
- Squeeze theorem (mathematical analysis)
- Stallings theorem about ends of groups (group theory)
- Stallings–Zeeman theorem (algebraic topology)
- Stanley's reciprocity theorem (combinatorics)
- Star of David theorem (combinatorics)
- Stark–Heegner theorem (number theory)
- Stein–Strömberg theorem (measure theory)
- Steiner–Lehmus theorem (triangle geometry)
- Steinhaus theorem (measure theory)
- Steinitz theorem (graph theory)
- Stewart's theorem (plane geometry)
- Stinespring factorization theorem (operator theory)
- Stirling's theorem (mathematical analysis)
- Stokes' theorem (vector calculus, differential topology)
- Stolper–Samuelson theorem (economics)
- Stolz–Cesàro theorem (calculus)
- Stone's representation theorem for Boolean algebras (mathematical logic)
- Stone's theorem on one-parameter unitary groups (functional analysis)
- Stone–Tukey theorem (topology)
- Stone–von Neumann theorem (functional analysis, representation theory of the Heisenberg group, quantum mechanics)
- Stone–Weierstrass theorem (functional analysis)
- Strassman's theorem (field theory)
- Strong perfect graph theorem (graph theory)
- Structure theorem for finitely generated modules over a principal ideal domain (abstract algebra)
- Structure theorem for Gaussian measures (measure theory)
- Structured program theorem (computer science)
- Sturm's theorem (theory of equations)
- Sturm–Picone comparison theorem (differential equations)
- Subspace theorem (Diophantine approximation)
- Supporting hyperplane theorem (convex geometry)
- Swan's theorem (module theory)
- Sylow theorems (group theory)
- Sylvester's determinant theorem (determinants)
- Sylvester's theorem (number theory)
- Sylvester pentahedral theorem (invariant theory)
- Sylvester's law of inertia (quadratic forms)
- Sylvester–Gallai theorem (plane geometry)
- Symmetric hypergraph theorem (graph theory)
- Symphonic theorem (triangle geometry)
- Synge's theorem (Riemannian geometry)
- Sz.-Nagy's dilation theorem (operator theory)
- Szegő limit theorems (mathematical analysis)
- Szemerédi's theorem (combinatorics)
- Szemerédi–Trotter theorem (combinatorics)
- Szpilrajn extension theorem (axiom of choice)
Read more about this topic: List Of Theorems