The applause lasted longer than it took to sign it in to law.
More than 20 years after homosexuality was decriminalised, same-sex couples can legally marry in Ireland from next Monday - paving the way for a high number of Christmas weddings.
The commencement order for the Marriage Act 2015 was signed yesterday by Justice Minister Frances Fitzgerald in Dublin Castle.
The historic event was ushered into law behind the backdrop of a minute-long thunderous applause and a standing ovation from the 300-strong crowd who had gathered for the occasion.
It is seen as one of the most dramatic legal changes as regards family life in the history of the state. Accompanying regulation - the 2004 Civil Registration Act - was also signed by Tánaiste Joan Burton.
It means thousands of gay couples can now marry in a matter of days.
Ms Burton said no words could do justice to her feelings following the "historic occasion".
"After so much hard work, this now makes marriage a reality for so many LGBT couples," she said.
Justice Minister Francis Fitzgerald said the event marked the end of the "journey to equality that was taken by the whole nation".
"The Irish people blazed a trail on May 22nd 2015 when they became the first sovereign people to choose marriage equality by popular vote," she said.
"It is a pleasure to sign this order in the company of some of the couples who will be able to marry in the coming weeks and months.
"The Marriage Act has profound symbolic importance, but will also have a real and tangible impact on their family life," she added.
Immediately after the referendum was passed six months ago, officials from the General Register Office began contacting same-sex partners who had booked civil partnerships to ask if they wished to proceed as planned or convert it to a formal wedding ceremony.
Each couple then provided the Register with a 'notice to marry' if they so wished.
Those who married in foreign jurisdictions before the referendum will also have their union recognised under Irish law.
Speaking afterwards, an emotional Bill Hughes said it was an amazing feeling that he and his partner of 18-years Gary Hodgkinson can finally wed.
"I still can't believe it. I still can't believe this is the Ireland we have grown up in," said the radio presenter and TV producer.
Davin Roche, of Gay Lesbian Equality Network (GLEN), said added: "It marks the end of a long legal journey."