This is a list of variational topics in from mathematics and physics. See calculus of variations for a general introduction.

• Action (physics)

• Averaged Lagrangian

• Brachistochrone curve

• Calculus of variations

• Catenoid

• Cycloid

• Dirichlet principle

• Euler–Lagrange equation cf. Action (physics)

• Fermat's principle

• Functional (mathematics)

• Functional derivative

• Functional integral

• Geodesic

• Isoperimetry

• Lagrangian

• Lagrangian mechanics

• Legendre transformation

• Luke's variational principle

• Minimal surface

• Morse theory

• Noether's theorem

• Path integral formulation

• Plateau's problem

• Prime geodesic

• Principle of least action

• Soap bubble

• Soap film

• Tautochrone curve