Formulas
- Stella octangula number
- Steradian
- Stewart's theorem
- Stiffness matrix
- Stille reaction
- Stochastic matrix
- Stoichiometry
- Stokes' theorem
- Stokes wave
- Stone–Weierstrass theorem
- Stopping power (particle radiation)
- Straightedge and compass construction
- Strain-rate tensor
- Stress–energy tensor
- String harmonic