In US constitutional law, a facial challenge is a challenge to a statute or regulation in which the plaintiff alleges that the legislation, by its written terms, is always unconstitutional and therefore is void under all circumstances and in all contexts. It is contrasted with an as-applied challenge, which alleges that a particular application of a statute is unconstitutional.
If a facial challenge is successful, a court will declare the statute in question facially invalid, which has the effect of striking it down entirely. This occurred in the case of West Virginia State Board of Education v. Barnette (1943).