Although the First Amendment generally guards against government censorship of speech, there are categories of speech that are not afforded constitutional protection. One of these categories is “fighting words.” This chapter analyzes the fighting words and examines its application to public-school censorship of student speech. The first part of this chapter discusses the United States Supreme Court’s decisions related to the fighting-words doctrine. The second examines examples of online communications in the K-12 and higher education contexts. The third part discusses cases in which courts have applied the fighting-words doctrine to student communications. The final part of this chapter analyzes whether public schools can justify the restriction of online student communication through the fighting-words doctrine.