The Minister for Justice and Equality Frances Fitzgerald has welcomed the President's signature signing same-sex marraige into law.
The Government can now bring forward legislation to allow same-sex marriages take place here, the first country in the world to do so based on a popular vote. This is expected to take place in September.
The same-sex marriage referendum was passed in May.
Sandra Irwin Gowran of equality group GLEN explained the Government now had to put in "enabling legistlation" ro allow the Civil Registration Act to be amended to reflect the 34th amendment to the Constitution.
"Soon after that you'll begin to see the first marriages of lesbian and gay couples. So it'll be a few months yet, but people can get saving for the big day," she said.