Deformation can refer to:
- Deformation (engineering), changes in an object's shape or form due to the application of a force or forces.
- Deformation (physics), such changes considered and analyzed as displacements of continuum bodies.
- Deformation (meteorology), a measure of the rate at which the shapes of clouds and other fluid bodies change.
- Deformation (mathematics), the study of conditions leading to slightly different solutions of mathematical equations, models and problems.
- Deformation (volcanology), a measure of the rate at which the shapes of volcanoes change.
- Deformation (biology), a harmful mutation or other deformation in an organism.