The principal of a Catholic secondary college in northern New South Wales is urging the school community to embrace two transgender students.

Brother John Hilet, the principal of Trinity Catholic College Lismore, said he felt privileged when two students confided in him that they were experiencing gender identity issues.

He said the students were born female but identified as male and were seeking to wear the designated boys uniform to school.

"I've had students in the past reveal they are same-sex attracted but never with gender identity issues, so I was a bit surprised," Brother John said.

"I was very quickly moved by their level of trust, faith and willingness to come forward and speak with me.

"They were moved at a very deep level and at that point the only response I could think of was to treat them with compassion and reach out and do whatever I could to assist."

Brother John Hilet sent a letter to parents when students told him they were experiencing gender identity issues. ( Supplied: Facebook )

Brother John said he sought advice from Lismore Bishop Gregory Homeming and the NSW Catholic Education Commission.

"I did speak with the local Bishop because I knew any move might cause some people to get concerned or upset and they would probably get in touch with him if they wish to express those views," Brother John said.

"His response to me was quite clearly that this is an issue of wellbeing for these students. It is an issue of being caring, compassionate and reaching out and doing what we can to assist. I was very happy that confirmed my feelings."

The students were granted permission to wear the boys uniform, while the school investigated the introduction of a gender neutral uniform option.

Brother John also sent a letter home to parents urging them to support the students:

I will address the other students about difference and respect and will point out that it is essential as a Catholic community we offer our full support to these students and that any comments seen as targeting or bullying these students will not be tolerated. I ask that you also support these students in any conversations you might have with your children.

He said that although the Church may be seen as conservative, the acceptance of transgender students fits within Catholic teachings.

"One of the things I said to the students was that it is a fundamental Catholic teaching that all human beings have an innate dignity that doesn't derive from anything other than the fact we are human and made in the image and likeness of God," Brother John said.

"When Jesus spoke he never taught us to do anything other than love others, so that was the way I expressed it.

"This dignity is inherent, it's not dependent on gender, sexuality, race, creed or anything like that.

"I don't tolerate targeting or bullying of any student, regardless of the cause."

Brother John said he had received 60 emails from parents replying to his letter, which was an unprecedented response.

"Invariably the responses have been incredibly positive, thanking the college for its openness and inclusiveness and overwhelmingly supporting the idea of a gender neutral uniform option," he said.

"The one that touched me most was a mother who indicated one of her children left the school about three years ago for the same reason and at the time didn't feel confident in coming to approach me and talk to me about it. And that was sad."