Formulas
- Pythagorean theorem
- Quadratic assignment problem
- Quadratic eigenvalue problem
- Quantifier (logic)
- Quasi-algebraically closed field
- Quasiregular element
- Quasisymmetric map
- Quincunx matrix
- Quiver (mathematics)
- Quotient space (topology)
- ROT13
- Racks and quandles
- Leon Mirsky
- Leonard Eugene Dickson
- Radial set