Formulas
- Deformation (mathematics)
- Deformed Hermitian Yang–Mills equation
- Degen's eight-square identity
- Degenerate distribution
- Degree matrix
- Degree of a field extension
- Degree of a polynomial
- Degree of an algebraic variety
- Dehn twist
- Dehornoy order
- Delannoy number
- Delaunay triangulation
- Delay differential equation
- Dependence relation
- Dependency graph