Tánaiste Joan Burton and Minister for Justice and Equality Frances Fitzgerald have welcomed a decision by Cabinet to hold the Marriage Equality referendum next May.
Ms Burton said: "The fact that this referendum is now 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 Fitzgerald said: "I believe that we should put a clear question to the people, asking them if same-sex couples should have a right to marriage equality.
"The referendum will provide an important opportunity for people to decide whether all couples, regardless of their sexual orientation, will have the opportunity to get married and to have constitutionally protected relationships."
It is understood that a number of referendums, including the one on same-sex marriage will be held in May, possibly in the first week.
A referendum to reduce the minimum age for presidential election candidates will also be held.
Candidates currently must be 35 years of age but the Government has agreed to hold a referendum to see whether it should be reduced to 21.
The Carlow-Kilkenny by-election to fill the seat vacated by Phil Hogan is also expected to take place on the same day as the referendums.