The First Amendment gives young people and others the right to express themselves through what they wear, with certain restrictions.
Student Dress Codes & T-shirts
Can the school tell me what—or what not—to wear to school?
In most cases. Schools have pretty broad leeway in creating rules on dress and clothing. Many times, they say the rules are to prevent distractions or prevent gang activity.
However, if your clothing relays a particular message, such as one about involvement in war or political and social issues, and it meets certain standards of protected speech, it's more likely to be protected by the First Amendment.
That said, a school's dress code by law must be clear, reasonable, fair, understandable, and serve a school's educational mission.
A dress code that simply bans "gang colors," for example, would be unconstitutional because determining what is or is not a gang color would be impossible. On the other hand, requiring all students to wear school uniforms is more likely to be allowed by the legal system because the rule is specific and isn't attempting to ban students from expressing their beliefs.
Can a school’s dress code keep us from wearing shirts that have certain slogans or messages on them?
It depends. Some schools, to avoid the problem, ban any shirt that has a message on it, and that may be allowed by law. However, if the school does allow students to wear shirts with messages, it cannot ban any particular message unless it's obscene, vulgar, or promotes illegal activities (such as drinking) or intrudes on the rights of others (such as personal harassment).
Particularly if a shirt has a political or religious message, school officials can't ban your wearing it. In 2005, two students at Roosevelt High School in Des Moines wore shirts that said "abortion kills kids." They were told to cover up the wording or they would be punished. The two girls protested and the story ended up in the media. The ACLU also protested the school's ban. The school changed its policy and the students were allowed to wear the shirts.
Can the school make me wear a school uniform or a set outfit that’s like a uniform?
In some cases. Usually, it's private schools (which aren't government-funded) that have uniforms. However, more public schools are experimenting with requiring a student uniform or something close to it.
Waterloo schools imposed a conservative dress code. That dress code restricts students to shirts in certain solid colors with collars and solid-color pants, such as khakis, and banned jeans. Parents and students fought the code, saying it was too restrictive and violated state law. But the Iowa Board of Education ruled that school districts could indeed have a dress code such as this one.