The publication or utterance of blasphemous matter is an offence specified by the Constitution of Ireland as an exception to general guarantee of the right of the citizens to express freely their convictions and opinions.

In Corway v Independent Newspapers (1999), the Supreme Court held that the common law crime of blasphemous libel related to an established church and could not have survived the enactment of the Constitution.

[5] The offence of publishing or uttering blasphemous matter was first defined in Irish law in the Defamation Act 2009.

There is a broad defence where "a reasonable person would find genuine literary, artistic, political, scientific, or academic value in the matter to which the offence relates".

[7] In June 2018, Minister for Justice and Equality Charles Flanagan announced that the government would hold a referendum to simply remove the reference to the offence of blasphemy from the Constitution.

[17] Minister for Housing, Planning and Local Government Eoghan Murphy signed the electoral order for the referendum on 21 September, setting the polling date as 26 October.

In Dublin some estimates suggested that turnout would be half that of the referendum on the Thirty-sixth Amendment of the Constitution of Ireland in May.

[38] RTÉ noted that given that the presidential election had received far more attention, it had been expected that there would be more abstainers than the 1.8% reported in its exit poll data.