Matthayom Wat Thatthong School in Bangkok's Watthana district is letting students express their gender identity through their hair and dress after ending its short-hairstyle policy two years ago.
The move has been welcomed as a step towards inclusiveness, with no reported issues during the two-year period.
The school allows secondary students to wear their hair to their preference and gender identity.
The school recently issued a new policy which lays out clearer rules on student hair and dress with an emphasis on student rights.
Students can wear their hair long or short depending on their preference, but those who identify as female must tie their hair back with the school uniform bow "in an appropriate and tidy manner".
Hair dyeing and beards or moustaches remain prohibited.
The school policy comes after Education Minister Trinuch Thienthong lifted "unfair" hairstyle rules on Jan 23, following calls going back years for more relaxed hair regulations from the public, academics, parents, and students.
The Bangkok Post spoke to several students about the relaxed hair rules.
"I feel liberated," Supayu Phaomahamad, 15, said. "As a teenager, I want to appear my best, and having the ability to wear my hair however I want lets me do that," he added.
Ekawee Wangchao, another student, says the looser rules have brightened up his school life. "Having longer hair makes me more confident," he said.
"Makeup or no makeup, short or long hair, none of this is related to academic achievement," Soraphanaya Siphumueang, 14, said.
