The Thirty-first Amendment of the Constitution (Children) Act 2012 (previously bill no. 78 of 2012) amended the Constitution of Ireland by inserting clauses relating to children's rights and the right and duty of the state to take child protection measures. It was passed by both Houses of the Oireachtas (parliament) on 10 October 2012, and approved at a referendum on 10 November 2012, by 58% of voters on a turnout of 33.5%. Its enactment was delayed by a High Court case challenging the conduct of the referendum. The High Court's rejection of the challenge was confirmed by the Supreme Court on 24 April 2015. It was signed into law by the President on 28 April 2015.
 According to Aoife Nolan, "The limited consideration of children (and of children as right‐holders, specifically) in the 1937 Constitution is undoubtedly largely attributable to the contemporary societal perception of children as objects of parental rights and duties rather than autonomous right‐holders." The Constitution's framing of family and education rights in Articles 40 to 44 reflected Catholic social teaching as in Quadragesimo anno.  Over the 1990s and 2000s, a political consensus developed in Ireland that children's rights needed to be strengthened in the Constitution to counterbalance family rights.  Numerous contemporary and historical cases of child abuse and neglect came to light, including  many involving the Catholic Church. Reports, including that of the Commission to Inquire into Child Abuse and another by Catherine McGuinness, found that state agencies' hesitancy to act was partly from fear that hasty intervention might violate the parental rights guaranteed by the Constitution. There were other controversial constitutional judgments in court cases involving minors: "Baby Ann" was placed for adoption by unmarried parents aged one week and returned to them after two years when they married, despite having bonded with foster parents in the interim; and a man found guilty underage sex, after his defence of mistaken age had been ruled inadmissible under strict liability, had his conviction overturned when the strict-liability provision was ruled unconstitutional.
 The 1996 Constitution Review Group recommended: 
 The All-Party Oireachtas Committee's 2006 report on the family proposed inserting a section into Article 41:
 A children's rights bill, the Twenty-Eighth Amendment of the Constitution Bill 2007, was introduced by the Fianna Fáil–PD government. The bill sought to replace section 5 of Article 42 with a new Article 42A, which had five sections; the first four broadly matched the amendment eventually enacted in 2015, while the fifth was:
 The 2007 bill lapsed when the 29th Dáil was dissolved for the 2007 general election. All main parties' election manifestos promised a children's referendum. After the election, the 30th Dáil and 22nd Seanad passed parallel resolutions establishing a joint committee to consider the 2007 bill as the basis for a new amendment proposal. The committee requested public comment, held hearings, and issued reports. Its final report in February 2010 proposed a complete rewrite of Article 42 of the Constitution. The Fianna Fáil–Green Party government finalised the wording for an amendment bill in January 2011, just before the Green Party left government precipitating the 2011 general election. The bill which eventually passed was introduced by the new Fine Gael–Labour government in September 2012, substantially differing from the 2010 recommendation.
 Section 5 of Article 42 was deleted. A new Article 42A was inserted after Article 42. The changes to the text are as follows (the differences between the old 42.5 and the new 42A.2.1º are highlighted):
 Subsection 5 from Article 42:
 Two days before the referendum was held, in McCrystal v. Minister for Children the Supreme Court ruled that the government had breached the constitution by using public funds to publish and distribute information concerning the referendum that was biased in favour of a yes vote. In 1995 in the case of McKenna v. An Taoiseach, the Supreme Court had ruled that public funds should be used for explaining referendums in an impartial manner. While a statutory Referendum Commission fulfilled the latter role, the Minister for Children and Youth Affairs had published a separate booklet and webpages which were found to be non-neutral.
 On 19 November 2012, two women, Joanna Jordan and Nancy Kennelly, brought petitions to the High Court challenging the referendum result, claiming that the unlawful use of public funds by the government had materially affected the outcome. Kennelly, who claimed she had voted Yes based on misleading advice in the government campaign, withdrew her petition the following week. The case of Jordan, who was active in the No campaign, was adjourned pending the handing down of written judgements in the McCrystal case, which occurred on 11 December 2012. Jordan's case was heard in April and May 2013, with expert witnesses differing on the interpretation of a Behaviour & Attitudes survey of voters carried out for the Referendum Commission after polling day. Judgment was reserved on 16 May 2013.
 On 18 October 2013, judge Paul McDermott rejected the petition, ruling that Jordan had failed to prove the government's advocacy had "materially affected" the referendum result. McDermott ordered a two-week stay on the delivery of the final referendum certificate, to give Jordan an opportunity to appeal his decision to the Supreme Court. An appeal was duly lodged on 24 October. Jordan's original challenge to the referendum was made and processed by the procedure prescribed in the Referendum Act 1994; after the High Court case, she launched a separate challenge to the constitutionality of those provisions, arguing they placed too high a burden of proof on the petitioner. This challenge was also rejected by McDermott in the High Court, on 19 June 2014. Jordan was allowed to appeal against both High Court decisions at the same time; her case was heard by the Supreme Court at the start of December 2014. On 24 April 2015, the Supreme Court upheld both High Court decisions.
 In June 2018, Joanna Jordan was one of three petitioners challenging the validity of the Referendum to legalise abortion.
 Prior to the 2012 referendum, the government published the general scheme of an amendment to the Adoption Act which it promised to enact after the constitutional amendment. After the 2016 general election, the new Fine Gael–led government introduced the bill in May 2016.
 In September 2015, Alan Shatter introduced a private member's bill to amend the Referendum Act 1994 such that any referendum petition would be heard immediately in the Supreme Court. This was intended to prevent recurrence of such a long delay between a referendum and the enactment of the concomitant constitutional amendment.
 In 2016, Justice Richard Humphreys ruled in the High Court that rights of the unborn were not limited to the right to life specified in the Eighth Amendment, but rather included others such as those specified in the 31st Amendment. This contradicted a 2009 ruling by Justice John Cooke. An appeal to the 2016 decision was upheld by the Supreme Court of Ireland in 2018.