The school has also prohibited the students from participating in any extracurricular activities for the rest of the school year, including prom, sports, junior achievement, and various groups, Sorcha Beirne told CBC News on Friday.
The students are mostly facing three-day suspensions, although Beirne is facing a five-day suspension.
But school principal Shane Thomas says the students were not suspended for protesting, but rather for violating the "positive learning workplace" policy.
The suspensions relate to an incident outside the administrative office, said Thomas. Students who only protested were not suspended, he said.
Anglophone West School District Superintendent David McTimoney could not immediately be reached for comment.
About 20 students, led by members of the group Fredericton Youth Feminists, walked out of class on Nov. 21 to protest and were subsequently locked out by the school.
Thomas wouldn't say exactly how many students were suspended, but did say it was "more than a dozen."
He also says the students are suspended from their classes, but not from the school.
Students will have academic support available to them over the course of the suspension, says Thomas.
The students contend the dress code in the Anglophone West School District unfairly targets female students and has led to female students being kicked out of class.
They also say the rules place the blame for sexual assault and harassment onto the victim.
In a statement released Friday evening, the Fredericton Youth Feminists highlighted the impact the suspensions could have on students' academic futures.
"Being barred from extracurricular activities is limiting student’s scholarship and post-graduate opportunities, as well as their chances to develop skill sets," said the statement.
Beirne is the spokesperson for the group.