The Government has cleared the way for a referendum on same-sex marriage to take place next May.
A referendum will also take place on the same day to reduce the age of presidential candidates from 35 to 21.
In the Dail, Taoiseach Enda Kenny confirmed that the Cabinet had given approval for both referendums.
"The Cabinet gave approval to hold the referenda, and both referenda will happen on the one day in the month of May 2015. The Government did not fix a final date," he said.
Mr Kenny added that Justice Minister Frances Fitzgerald will come back to the Dail when she has finalised her proposals in relation to the same-sex marriage question.
It is expected that the two referendums will take place on the same day as the Carlow-Kilkenny by-election to fill the Dail seat vacated with the resignation of former minister Phil Hogan, who is now Ireland's EU Commissioner.
The Taoiseach said the Government will also now move to create a commission to oversee the holding of the two referendums.
Welcoming the decision, Tanaiste Joan Burton said the decision by the Cabinet that the Marriage Equality referendum will take place in May was a "very positive and progressive development".
"The fact that this referendum is to take place is a mark of the progress that has taken place in this country in recent years and decades, and indicates the extent to which attitudes to lesbian and gay people have changed," Ms Burton said.
Junior justice minister Aodhan O Riordain also welcomed the decision.
"I am delighted to see that the Government has approved today's memorandum on the holding of a Marriage Equality Referendum next year," he said.
"It will provide the people of Ireland with the opportunity to have their say on what is a crucial equality issue.
"The approach that was agreed to today will, I hope, allow for a calm and considered debate on the topic, and I look forward to taking part in the future discussions."
The Government also approved a referendum to reduce the voting age of presidential candidates from 35 to 21.
This was a move approved by the Constitutional Convention last year. Environment Minister Alan Kelly brought a memo to Cabinet yesterday for approval of draft legislation.
The radical move comes as the Government looks set to hold at least four referendums next year.
Sources have confirmed that the move to reduce the age is part of a drive to make the presidency more relevant to younger people. However, it was passed by only three votes.