Schools often have a dress code that requires school uniforms or that limits clothing styles—such as policies of no tank tops, shorts, low-cut tops, pants worn below the waistline, or suggestive, provocative, or controversial messages. Some schools extend these dress code policies to hairstyles, headwraps, hair color, and facial hair.

These policies are sometimes challenged by students on free speech grounds (under the First Amendment to the U.S. Constitution) and on discrimination grounds. Schools are required to meet a high burden to justify restricting their students’ right to freedom of speech.

Each school policy and claim of a violation of law must be evaluated on a case-by-case basis but schools are generally allowed to restrict clothing, speech, and hairstyle choices only if they would likely disrupt the educational environment of the school and interfere with school activities—including by causing tension and discord among the students or teachers.

In New Hampshire, schools may implement dress codes and policies that regulate student attire, hairstyles, and other aspects of appearance. These policies are generally upheld as long as they aim to promote a safe and distraction-free educational environment. However, when students challenge these policies on the grounds of free speech (protected under the First Amendment) or discrimination, schools must demonstrate that the restrictions are necessary to prevent a substantial disruption of or material interference with school activities. The U.S. Supreme Court's decision in Tinker v. Des Moines Independent Community School District (1969) established that students do not 'shed their constitutional rights to freedom of speech or expression at the schoolhouse gate.' Therefore, any limitations on student expression, including dress codes, must be carefully scrutinized to ensure they do not infringe upon these rights without sufficient justification. Each case involving a challenge to school dress code policies is assessed individually, considering the specific circumstances and the policy's impact on the school environment.