A 17-year-old student in Tennessee is suing his school district and two top school officials for the three-day suspension he received after he posted satirical memes about the principal on social media when he was not on campus.

The student, identified in court documents only as I.P., is starting his senior year next month at Tullahoma High School in Tullahoma, Tenn., about 60 miles southeast of Nashville. The lawsuit accuses the defendants — Tullahoma City Schools; Jason Quick, the former principal; and Derrick Crutchfield, an assistant principal — of violating his First Amendment rights.

In 2022, I.P. posted three memes on his public Instagram account featuring Mr. Quick. None of the memes were uploaded while I.P. was on campus or during school hours, according to the lawsuit, which was filed on July 19 in U.S. District Court for the Eastern District of Tennessee.

One showed Mr. Quick holding a box of vegetables, to which I.P. added text that said, “like a sister but not a sister <33.” Another portrayed Mr. Quick in a dress with cat ears and whiskers, while a third meme showed the principal’s face superimposed on a video game character being hugged by a cartoon bird.

“I.P. intended the images to satirize, in I.P.’s view, Quick’s overly serious demeanor,” the lawsuit said.

I.P. was informed of the five-day suspension by Mr. Crutchfield in August 2022 after a meeting with Mr. Quick. The student had a panic attack, the lawsuit says, and the suspension was reduced to three days, the same punishment that applies to students in a fist fight.

The Foundation for Individual Rights and Expression, a free-speech advocacy group also known as FIRE, said in a statement that the student “intended the images to be tongue-in-cheek commentary satirizing a school administrator he perceived as humorless.”

Conor Fitzpatrick, a FIRE lawyer and the lead lawyer for the student, said on Monday that the heart of the issue is that as long as the posts do not “disrupt the school day, the school cannot censor it.” He said that I.P. is asking that his suspension be expunged from his record and that he is also seeking unspecified monetary damages from a jury trial.

Mr. Fitzpatrick said the student’s legal team is also asking the court to prevent the high school from enforcing its social media policy. The policy says social media use that is “unbecoming” of a student, or the distribution of photographs, video or recordings that are “embarrassing, demeaning, or discrediting” to students or staff members could be subject to discipline, including suspension.

A woman who answered the phone at the high school on Monday said she was unable to comment. A receptionist for the district took a message, but there was no comment from officials there. Mr. Quick, who stepped down as principal on June 30, referred questions to his lawyer, W. Carl Spining, who did not immediately reply to a voice mail message seeking comment.

Mr. Crutchfield could not be reached.

Courts in the United States have previously ruled on whether schools have the power to oversee or discipline students’ behavior off campus and outside of school hours. The Supreme Court ruled in 2021 that a Pennsylvania school district had violated the First Amendment rights of a student by suspending her from the cheerleading squad after she posted vulgar messages about the school on Snapchat while she was not on school grounds.

The Tennessee lawsuit said the First Amendment prevents public school employees from acting as a “round-the-clock board of censors” over student expression, which in I.P.’s case were “nondisruptive” and “nonthreatening.”

“The Supreme Court has been clear: Unless a student’s off-campus expression causes a substantial disruption at school, the job of policing their speech falls to parents,” the lawsuit said, “not the government.”