The decision of RTÉ radio presenter Jonathan Clynch to identify himself as "gender fluid" has been met with support by his employers and equality groups.
When Mr Clynch (44) returns from annual leave later this month, he will be referred to as Jonathan Rachel.
He reportedly told his employers that he now identifies as gender fluid and will be dressing as a woman at times.
"It is very personal and a very difficult step for him/her," said Sarah Phillips, chair of the Transgender Equality Network Ireland (TENI) and facilitator of the Dublin Trans Peer Support Group.
"But employers, family and friends, including myself, are very supportive of him/her.
"It is important to speak regarding gender identity and continue that conversation and dialogue, to improve the broader education among wider society of gender identity."
Mr Clynch, who has worked at RTÉ for the past 16 years, was due to appear on The Marian Finucane Show at the weekend but pulled out after his story featured in a newspaper.
"After today's front page, Jonathan wants to speak about his decision on his own terms," said Ms Finucane.
In a statement RTÉ said: "We, both as an employer and broadcaster, value the uniqueness of individuals and encourage diversity and equality.
"We are 100pc supportive of Jonathan Rachel who is a valued member of staff and a highly respected journalist."
Ms Phillips said it is difficult to provide a clear definition of gender fluidity, which depends on the individual.
"A gender fluid person is between binary gender - they are not within the gender binaries of man and woman.
"They identify at different times as male or female or a bit of both."
Ms Phillips believes that the news about Jonathan Rachel Clynch may serve to highlight shortcomings in new transgender legislation.
The Gender Recognition Act 2015, enacted last week, enables transgender people to obtain a birth certificate which shows their preferred gender.
"It does not include those on the non-binary spectrum, those under the age of 16 or people with an intersex condition," she said, but added that it was "one of the most progressive pieces of legislation in the world".