The cheval de frise (plural: chevaux de frise [ʃə.vo də fʁiz], "Frisian horses") was a defensive obstacle, existing in a number of forms, principally as a static anti-cavalry obstacle but also quickly movable to close breaches. The term was also applied to underwater constructions used to prevent the passage of ships or other vessels on rivers. In the anti-cavalry role the cheval de frise typically comprised a portable frame (sometimes just a simple log) with many projecting spikes. Wire obstacles ultimately made this type of device obsolete.

During the American Civil War the Confederates used them more than the Union forces. During World War I, armies used chevaux de frise to temporarily plug gaps in barbed wire. Barbed wire chevaux de frise were used in jungle fighting on the South Pacific islands during World War II.

The term is also applied to defensive works on buildings. This includes a series of closely set upright stones found outside the ramparts of Iron Age hillforts in northern Europe, or iron spikes outside homes in Charleston, South Carolina.