Leo Varadkar said he hopes the referendum will be held this summer. The date of the referendum and its wording have not been worked out yet.
Varadkar told BBC radio that he will call for an easing of the extremely strict laws against abortion in Ireland, which bans the procedure even in cases of rape and cases where the fetus is suffering potentially fatal abnormalities.
The prime minister says his views have "evolved" since he described himself as "pro-life" in 2014.
He says the government should be finalising details about the referendum in the coming week. It is expected to involve the possible repeal of a 1983 constitutional amendment greatly restricting access to abortions.
Recent opinion surveys suggest there is public support for moderating the laws so that women could have abortions in the first 12 weeks of pregnancy.