St. Mary's Catholic high school has a policy on uniforms that excludes facial jewelry except for "unobtrusive ear piercing," the London (Ontario) Free Press reported Friday.
Principal Ana Paula Fernandes, who started the job this month, told the newspaper the policy was at least 3 years old and outlined in the students' planners.
"Students sent down to the office are given the option to remove the piercings or leave the school," she said. "The policy is what it is and that's what I'm enforcing."
Students are given the choice of removing the metallic piercings during class or face expulsion, the newspaper said.
When students pointed out one teacher at the school who wears a nose stud, Fernandes issued a staff advisory teachers had to comply as well.
Protesting student Kyle Walker said the school was sending mixed messages.
"At the assemblies, they tell you to be yourself," he told the newspaper. "If they're not letting you express yourself, how is that being yourself?"