Gay Byrne has died at the age of 85, following "a very difficult illness".
The legendary broadcaster was best known for hosting The Late Late Show.
President Higgins said Gay Byrne "was a man of great charisma, who exuded warmth and presence".
Ryan Tubridy has called him "a friend and mentor", "a master" and a "once off".
In 2004, The Irish Film & Television Awards awarded Gay Byrne with its lifetime achievement award.
He is survived by his wife, broadcaster Kathleen Watkins, two daughters Suzy and Crona and grandson Cian.
Born in 1934, Gay Byrne would go on to forge a legendary career in Irish broadcasting, which touched the lives of millions.
Starting out with a 15 minute slot on Radio Eireann, he would go on to work in the UK for both Granada and the BBC, before landing his defining role.
Although conceived as a light entertainment show, the programme never shyed away from subjects which challenged the views of a conservative Ireland.
Viewers were captivated - whether it was the Bishop and The Nightie scandal, Byrne's compassionate response to calling a competition winner whose daughter had just died, and the hosts refusal to shake Gerry Adams hand.
Byrne would also give a platform for Irish artists such as U2, Sinead O'Connor and Boyzone.
Gay Byrne would remain at the helm of the Late Late until 1999.
Millions would also allow the Dubliner into their homes through the airwaves, with the Gay Byrne Show running on RTE Radio 1 for 25 years, and Uncle Gaybo presenting other favourites such as Who Wants to be a millionaire, and the meaning of life.
The Lord Mayor of Dublin, Paul Mc Auliffe, will open a Book of Condolence for Gay Byrne.
The public will be able to sign it at The Mansion House:
- Tuesday 5th November 2019 11am – 5pm
- Wednesday 6th November 2019 10am – 5pm
There will be a Late Late Show tribute to Gay Byrne on Tuesday night at 9.35pm on RTE One.
