In Physics and mathematics, a nonholonomic system is a system in which a return to the original internal configuration does not guarantee return to the original system position. In other words, unlike with a Holonomic system, the outcome of a nonholonomic system is Path (topology)-dependent.

For example, when riding a two-wheeled cart, a return to the original internal (wheel) configuration does not guarantee return to the original system (cart) position.

Automobiles, bicycles and unicycles are all examples of nonholonomic systems.

The branch of mathematics dealing with nonholonomic systems is known as sub-Riemannian geometry.

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