Last year there were 1,056 same-sex marriages in the Republic, 606 of these were male unions and were 450 female. There were more than 22,000 marriages and civil partnerships overall in 2016.
Last year is the first full year for which there are figures on same-sex marriages.
Same-sex marriage was legalised in November 2015, and that year there were 91 marriages. This rose to 1,056 in 2016.
In same sex marriages the average age of a man was 40.5 years, and female 41. The CSO says that over time it is expected these ages will fall.