Barnes v. Glen Theatre, Inc., 501 U.S. 560 (1991), was a landmark decision of the U.S. Supreme Court concerning the First Amendment and the ability of the government to outlaw certain forms of expressive conduct.

It ruled that the state has the constitutional authority to ban public nudity, even as part of expressive conduct such as dancing, because it furthers a substantial government interest in protecting the morality and order of society.

Glen Theatre was primarily in the business of selling adult entertainment materials, such as magazines and videos, and had an enclosed "bookstore" area where customers could insert coins into a machine which would allow them to view live female exotic dancers.

The respondents, represented by Patrick Baude, professor at Indiana University School of Law – Bloomington, argued that the prohibition of complete nudity in public places was unconstitutionally overbroad.

The opinions authored by the judges on the Seventh Circuit's panel accepted the argument that the statute in question unduly infringed on freedom of expression; in this case, the message of "eroticism and sexuality" that the dancers were meant to convey.

While the plurality ceded this point, it went on to decide how much constitutional protection the conduct warranted, and whether the statute at hand was, in fact, an unacceptable infringement on the freedom of expression.

Considering available precedent from cases such as Roth v. United States (1957)[7] and Bowers v. Hardwick (1986),[8] the plurality concluded that the statute furthered a government interest in order and morality.

Public nudity is the evil the state seeks to prevent, whether or not it is combined with expressive activity.As to the final point of the O'Brien test, the plurality contended that the statute was narrowly tailored to achieve the government interest it sought to promote.

Even though, as the respondents contended, the patrons in their establishments are all of legal age and all willing to see the prohibited nudity, the fact remains that, for the purposes of the constitutional question at hand, the statute was not needlessly restrictive.

In effect, this ruling determined that it was not unconstitutional for a state to enact legislation forbidding public nudity outright, particularly if the only requirement for a person to no longer be considered "nude" was wearing some of the most revealing possible clothing.

In the closing of his opinion, Justice Souter notes that the establishments are perfectly free to convey their erotic message in any other way short of violating obscenity laws.