Figures from Census 2011 reveal the number has jumped from 35,059 in 2002 to 87,770 in 2011. However, Ireland continues to have one of the lowest divorce rates in Europe.
The increase in the number of divorced people has driven the marital breakdown rate up from 8.7% in 2006 to 9.7% in 2011.
In contrast, the number of people identified as separated has levelled off at 116,194, up marginally from 107,263 five years earlier.
As divorce generally requires a period of separation in the first instance, the CSO said the figures reflect both a progression for people from separation to divorce, combined with new numbers joining the category of separation.
The highest rates of marital breakup were in the cities, topped by Limerick City with a rate of 13.5%, while Galway county had the lowest rates (7.5%). The marriage rate has remained relatively stable at 37%.
The number of people re-marrying following divorce has more than doubled since 2002.
The figures also show the numbers of cohabiting couples is also on the rise, but at a slower rate than previous years. Of the 1.18m families in Ireland, 143,600 were comprised of cohabiting couples.
There was 6% increase in the number of children of married couples. Among cohabiting couples this increase was 41%. There was also a 14% increase in the number of children of lone mothers.
Census 2011 shows an almost 100% increase in the number of same-sex couples living together since the last poll in 2006. There were 4,042 same-sex couples living together, comprising of 2,321 male couples and 1,721 female.
Some 230 of these couples had children, with the vast majority of these being female couples.
Most same-sex couples were found to be cohabiting with 166 indicating that they were married couples.
“As same-sex civil unions had only recently been introduced in Ireland at the time of the census in April 2011, it is likely that most of these were married abroad,” the study found.
Gay and Lesbian Equality Network chairman Kieran Rose welcomed the findings. “It is great to see the increasing confidence of lesbian and gay people leading to greater numbers recording their relationships in the census, even though these figures are likely to be an undercount,” he said.
The size of Irish households continues to shrink. There is now an average of 2.73 persons in each home, down from 2.81 in 2006.
The largest growth in the numbers of households is among couples with children, which account for 35% of all Irish households.