Irish nationality law is the law of the Republic of Ireland governing citizenship.^[1] A person may be an Irish citizen through birth, descent, marriage to an Irish citizen or through naturalisation. Irish nationality law is currently contained in the provisions of the Irish Nationality and Citizenship Acts 1956 to 2004 and in the relevant provisions of the Constitution of Ireland. The law extends extra-territorially to people born in Northern Ireland.

A person born on the island of Ireland on or after 1 January 2005:^[2]

• is automatically an Irish citizen if he or she is not entitled to the citizenship of any other country;^[3] or
• is entitled to be an Irish citizen if at least one of his or her parents is:
  • an Irish citizen (or someone entitled to be an Irish citizen);^[4]
  • a British citizen;^[5]
  • a resident of the island of Ireland who is entitled to reside in either the Republic or in Northern Ireland without any time limit on that residence;^[6] and/or
  • a legal resident of the island of Ireland for three out of the 4 years preceding the child's birth (although time spent as a student or as an asylum seeker does not count for this purpose).^[7]

A person who is entitled to become an Irish citizen becomes an Irish citizen if:

• he or she does any act that only Irish citizens are entitled to do; or
• any act that only Irish citizens are entitled to do is done on his of her behalf by a person entitled to do so.^[8]

Ireland previously had a much less diluted application of jus soli (the right to citizenship of the country of birth) which still applies to anyone born on or before the 31 December 2004.

Anyone born on the island of Ireland between 2 December 1999^[9] and 31 December 2004 (inclusive) was:

• entitled to be an Irish citizen and,^[10]
• automatically an Irish citizen if he or she was not entitled to the citizenship of any other country.^[11]

Before the 2 December 1999, the distinction between Irish citizenship and entitlement to Irish citizenship rested on the place of birth. Any person born on the island of Ireland was:

• automatically an Irish citizen if born in the Republic of Ireland; or
• entitled to be an Irish citizen if born in Northern Ireland.^[12]

Like most countries, Ireland does not normally grant citizenship to the children of diplomats. This does not apply, however, when a diplomat parents a child with an Irish citizen, a British citizen or a permanent resident.^[13] In 2001 Ireland enacted a measure which allowed the children of diplomats to register as Irish citizens if they chose to do so, however this was repealed three years later.^[14]

A person is an Irish citizen by descent if at the time of his or her birth at least one of his or her parents was an Irish citizen.^[15] In cases where at least one parent was an Irish citizen born in Ireland^[15] or an Irish citizen resident abroad in the public service,^[16] citizenship is automatic and dates from birth. In all other cases citizenship is subject to registration in the Foreign Births Register.^[17] As of 1 January 1987^[18] the Irish citizenship of those individuals requiring registration, dates from registration and not from birth, as had been previously the case.

In practice, anyone with an Irish citizen grandparent born in Ireland, can easily claim Irish citizenship. His or her parent would have automatically been an Irish citizen and their own citizenship can be secured by registering themselves as in the Foreign Births Register. In contrast, those wishing to claim citizenship through an Irish citizen great-grandparent may be easily frustrated if their parents were not registered in the Foreign Births Register. Their parents can only transmit Irish citizenship to children born after they themselves were registered and not to any children born before registration.

Citizenship acquired through descent may be maintained indefinitely so long as each generation ensures its registration before the birth of the next.

All adoptions performed or recognised under Irish law confer Irish citizenship on the adopted child (if not already an Irish citizen) if at least one of the adopters was an Irish citizen at the time of the adoption.^[19]

As of 30 November 2005,^[20] citizenship must be acquired through the normal naturalisation process.^[21] The residence requirement is reduced from 5 to 3 years for the spouse of an Irish citizen.^[22]

Previously, the law allowed for the spouses of most Irish citizens to acquire citizenship post-nuptially by registration without residence in the island of Ireland, or by naturalisation.^[23]

• From 17 July 1956 to 31 December 1986,^[24] the wife (but not the husband) of an Irish citizen (other than by naturalisation) could apply for post-nuptial Citizenship. A woman who applied for this before marriage would become an Irish citizen upon marriage. This was a retrospective provision which could be applied to marriages made before 1956. However the citizenship granted was prospective only.^[25]

• Between 1 July 1986^[24] and 29 November 2005,^[20] the spouse of an Irish citizen (other than by naturalisation, honorary citizenship or a previous marriage) could obtain post-nuptial Citizenship after 3 years of subsisting marriage, provided the Irish spouse had held that status for at least 3 years. Like the provisions it replaced, the application of this regime was also retrospective.^[26]

The naturalisation to a foreigner as an Irish citizen is a discretionary power held by the Irish Minister for Justice. Naturalisation is granted on a number of criteria including good character, residence in the state and intention to continue residing in the state.

In principle the residence requirement is three years if married to an Irish citizen, and five years otherwise. For those not married to Irish citizens, residence must be in the Republic, while for spouses of Irish citizens, residence in Northern Ireland can also count. However, not all time spent in the Republic or in Northern Ireland will count for the purposes of naturalisation. Time spent seeking asylum will not be counted. Nor will time spent as an illegal immigrant. Time spent studying in the state by a national of a non-EEA state (i.e. a state other than European Union Member States, Iceland, Norway and Liechtenstein) will not count.

The Minister for Justice may waive the residency requirement for:

• the spouses and children of naturalised citizens;
• recognised refugees;
• stateless children;
• those resident abroad in the service of the Irish state; and
• people of "Irish descent or Irish associations".

Section 12 of the Irish Nationality and Citizenship Act, 1956 allows the President, on advice of the Government, to:

" ... grant Irish citizenship as a token of honour to a person, or the child or grandchild of a person who, in the opinion of the Government, has done signal honour or rendered distinguished service to the nation."^[27]

Although known as "honorary Irish citizenship" this is in fact legally a full form of citizenship, with entitlement to an Irish passport and the other rights of Irish citizenship on the same basis as a naturalised Irish citizen.

Among those who have had honorary Irish citizenship conferred on them are:^[28]

• Jack Charlton (and his wife) – for his achievements as manager of the Republic of Ireland national football team;
• Alfred Chester Beatty (1957) – art collector, philanthropist and founder of the Chester Beatty Library;
• Alfred Beit (1993) (and his wife) – art collector and owner of Russborough House;
• Tiede Herrema (1975) (and his wife) – Dutch businessman kidnapped by the Provisional IRA;
• Derek Hill (1999) – artist who discovered the Tory Island school of painting;
• Tip O'Neill (and his wife) – Irish-American and Speaker of the United States House of Representatives; and
• Jean Kennedy Smith (1998) – former United States ambassador to Ireland.

Plans were made to grant honorary Irish citizenship to U.S. president John F. Kennedy during his visit to Ireland in 1963 but this was abandoned owing to legal difficulties in granting citizenship to a foreign head of state.^[29]

An Irish citizen may renounce his or her citizenship if she or he is:

• eighteen years or older;
• ordinarily resident abroad; and
• is, or is about to become, a citizen of another country.

Renouncing Irish citizenship is done by lodging a declaration with the Minister for Justice. If the person is not already a citizen of another country the renunciation is only effective when he or she becomes such. Irish citizenship cannot be lost by the operation of the law of another country.^[30]

An Irish citizen born on the island of Ireland who renounces Irish citizenship remains entitled to be an Irish citizen and may resume it upon declaration.^[31]

While not positively stated in the Act, the possibility of renouncing Irish citizenship is provided for to allow Irish citizens to be naturalised as citizens of foreign countries whose laws do not allow multiple citizenship. While naturalised citizens may have their naturalisation certificates revoked if they gain the citizenship of another country, there is no provision requiring them to renounce any citizenship they previously held. Nor is there any provision of Irish law requiring citizens (other than by naturalisation) to renounce their Irish citizenship before becoming citizens of other countries.

A certificate of Naturalisation may be revoked by the Minister for Justice. Once revoked the person to whom the certificate applies ceases to be an Irish citizen. Revocation is not automatic and is a discretionary power of the Minister. A certificate may be revoked if it was obtained by fraud or when the naturalised citizen to whom it applies:

• resides outside the Republic of Ireland (or outside the island of Ireland in respect to naturalised spouses of Irish citizens) for a period exceeding seven years, otherwise than in the public service, without registering annually his or her intention to retain Irish citizenship, (this provision does not apply to those who were naturalised owing to their "Irish descent or Irish associations");
• voluntarily acquires the citizenship of another country (other than by marriage); or
• "has, by any overt act, shown himself to have failed in his duty of fidelity to the nation and loyalty to the State".^[32]

A notice of the revocation of a certificate of naturalisation must be published in Iris Oifigiúil (the official gazette of the Republic) and in the period from January 2002 to April 2005 no such notices were published.^[33]

Irish passports use the standard EU design, with a machine-readable identity page and 32, 48 or 64 visa pages. The identity page on older Irish passports was on the back cover of the booklet. Newly-issued passports have been redesigned with additional security features. The identity page is now a plastic card attached between the front cover and the first visa page. The cover bears the harp, the national symbol of Ireland, along with the words "European Union" and "Ireland" in English and Irish.

Irish citizenship originates from Article 3 of the 1922 Constitution of the Irish Free State. Anyone domiciled in Ireland on the coming into force of the constitution on 6 December 1922 was an Irish citizen if:

• he or she was born in Ireland;
• at least one of his or her parents was born in Ireland; or
• he or she had been ordinarily resident in Ireland for seven or more years before the 6th December 1922;

unless they chose not to accept Irish citizenship. However, while Irish citizenship dates from 1922 it was not until 5 April 1935 (when the Twenty-sixth Amendment of the Constitution of the Irish Free State came into force) that Irish citizenship applied internationally and not just domestically.

While the Constitution referred to those domiciled in the "jurisdiction of the Irish Free State", this was interpreted as meaning the entire island. This was based on the Anglo-Irish Treaty which defined the Free State as covering the entire island although Northern Ireland opted-out of the Free State within a few days of 6th December 1922.^[34] The significance of this was that Northern Ireland was considered to have been "within the jurisdiction of the Irish Free State" on the 6th December 1922.^[35]

The 1922 Constitution only provided for citizenship for those alive on 6 December 1922. No provision was made for those born after this date. As such it was a temporary provision which required the enactment of a fully-fledged citizenship law which by done by the Irish Nationality and Citizenship Act, 1935. This Act provided for, among other things:

• Irish citizenship by birth for anyone born within the Irish Free State on or after 6 December 1922;
• Irish citizenship by descent for anyone whose father was an Irish citizen at the time of his or her birth;
• a naturalisation procedure; and
• automatic denaturalisation for anyone who became a citizen of another country on or after reaching 21 years of age.

The Act also provided for the establishment of the Foreign Births Register.

The 1937 Constitution of Ireland simply maintained the previous citizenship body, also providing, as the previous constitution had done, that the further acquisition and loss of Irish citizenship was to be regulated by law.

In 1956 the Irish parliament enacted the Irish Nationality and Citizenship Act, 1956. This Act repealed the 1935 Act and remains, although heavily amended, the basis of Irish citizenship law. This act provided for Irish citizenship for anyone born in the island of Ireland whether before or after independence. The only limitations to which were that anyone born in Northern Ireland was not automatically an Irish citizen but entitled to be an Irish citizen and, that a child of someone entitled to diplomatic immunity in the state would not become an Irish citizen. The Act also provided for open-ended citizenship by descent and for citizenship by registration for the wives (but not husbands) of Irish citizens.

In 1986 the 1956 Act was amended by the Irish Nationality and Citizenship Act, 1986. This act was primarily concerned with removing various gender discriminatory provisions from the 1956 legislation and thus provided for citizenship by registration for the wives and husbands of Irish citizens.

The Act also restricted the open-ended citizenship by descent granted by the 1956 Act by dating the citizenship of third, fourth and subsequent generations of Irish emigrants born abroad, from registration and not from birth. This ended the rights of fourth and subsequent generations to citizenship to those whose parents had been registered before their birth. The Act provided for a six-month transitional period during which the old rules would still apply. Such was the increase in volume of applications for registration from third, fourth and further generation Irish emigrants, the Irish Nationality and Citizenship Act, 1994 was enacted to deal with those individuals who applied for registration within the six-month period but who could not be registered in time.

Up until the late 1990s, jus soli, in the Republic, was maintained as a matter of statute law, the only people being constitutionally entitled to citizenship of the Irish state post-1937 were those who had been citizens of the Irish Free State before its dissolution. However, in 1998 as part of the new constitutional settlement brought about by the Belfast Agreement, the Nineteenth Amendment of the Constitution of Ireland provided (among other things) that:

"It is the entitlement and birthright of every person born in the island of Ireland, which includes its islands and seas, to be part of the Irish nation. That is also the entitlement of all persons otherwise qualified in accordance with law to be citizens of Ireland."

The introduction of this guarantee resulted in the enshrinment of jus soli as a constitutional right for the first time.^[36] In contrast the only people entitled to British citizenship as a result of the Belfast Agreement are people born in Northern Ireland to Irish citizens, British citizens and permanent residents.

If immigration was not on the political agenda in 1998, it did not take long to become so afterwards. Indeed soon after the agreement, the already rising strength of the Irish economy reversed the historic pattern of emigration to one of immigration, a reversal which in turn resulted in a large number of foreign nationals claiming a right to remain in the state based on their Irish-born citizen children.^[37] They did so on the basis of a 1989 Supreme Court ruling Fajujonu v. Minister for Justice where the court prohibited the deportation of the foreign parents of an Irish citizen. In January 2003 the Supreme Court distinguished the earlier decision and ruled that it was constitutional for the Government to deport the parents of children who were Irish citizens.^[38] This latter decision would have been thought to put the matter to rest but concerns remained about the propriety of the (albeit indirect) deportation of Irish citizens and what was perceived as the overly generous provisions of Irish nationality law.

In March 2004 the government introduced the draft Bill for the Twenty-seventh Amendment of the Constitution of Ireland to remedy what the Minister for Justice, Michael McDowell, described as an "abuse of citizenship" whereby citizenship was "conferred on persons with no tangible link to the nation or the State whether of parentage, upbringing or of long-term residence in the State".^[39] The Amendment did not propose to change the wording of Articles 2 and 3 as introduced by the Nineteenth Amendment, but instead to insert a clause clawing back the power to determine the future acquisition and loss of Irish citizenship by statute, as previously exercised by parliament before the Nineteenth amendment. The government also cited concerns about the Chen case, then before the European Court of Justice, in which a Chinese woman who had been living in Wales had gone to give birth in Northern Ireland on legal advice. Mrs. Chen then pursued a case against the British Home Secretary to prevent her deportation from the United Kingdom on the basis of her child's right as a citizen of the European Union (derived from the child's Irish citizenship) to reside in a member state of the Union. (Ultimately Mrs. Chen won her case but this was not clear until after the result of the referendum.) Both the proposed amendment and the timing of the referendum were contentious but the result was decisively in favour of the proposal; 79% of those voting voted yes, on a turnout of 59%.^[40]

The effect of the amendment was to prospectively restrict the constitutional right to citizenship by birth to those who are born on the island of Ireland to at least one parent who is (or is someone entitled to be) an Irish citizen. Those born on the island of Ireland before the coming into force of the amendment continue to have a constitutional right to citizenship. Moreover jus soli primarily existed in legislation and it remained, after the referendum, for parliament to pass ordinary legislation that would modify it. This was in fact done by the Irish Nationality and Citizenship Act 2004 (the effects of which are detailed above). It remains, however, a matter for the legislature and unrestricted jus soli could be re-established by ordinary legislation without a referendum.

• British nationality law
• British nationality law and the Republic of Ireland
• Common Travel Area
• Jus sanguinis
• Jus soli
• Articles 2 and 3 of the Constitution of Ireland
• Twenty-seventh Amendment of the Constitution of Ireland
• Irish Diaspora

• J.M. Kelly, The Irish Constitution 4th edn. by Gerard Hogan and Gerard Whyte (2002) ISBN 1854758950

• Irish Naturalisation and Immigration Service: Citizenship government website
• Repealed Acts of the Irish Free State:
  • Irish Nationality and Citizenship Act, 1935
  • Irish Nationality and Citizenship (Amendment) Act, 1937
• Acts in force:
  • Irish Nationality & Citizenship Acts 1956-2004 (unofficial consolidated version) - pdf format
  • Irish Nationality and Citizenship Act, 1956
  • Irish Nationality and Citizenship Act, 1986
  • Irish Nationality and Citizenship Act, 1994
  • Irish Nationality and Citizenship Act, 2001
  • Irish Nationality and Citizenship Act 2004
• Information on Irish citizenship from the Citizens Information Board
• Wives, mothers and citizens - the treatment of women in the 1935 Nationality & Citizenship Act
• Irish Nationality and Citizenship Bill, 1985: Second Stage
• Irish Nationality and Citizenship Bill, 1994: Second Stage