In mathematics, a convex body in n-dimensional Euclidean space is a compact convex set with non-empty interior.

A convex body K is called symmetric if it is centrally symmetric with respect to the origin, i.e. a point x lies in K if and only if its antipode, −x, also lies in K. Symmetric convex bodies are in a one-to-one correspondence with the unit balls of norms on R.