Referendums related to the European Union

This is a list of referendums related to the European Union, or referendums related to the European Communities, which were predecessors of the European Union. Since 1972, a total of 48 referendums have been held by EU member states, candidate states, and their territories, with several additional referendums held in countries outside the EU. The referendums have been held most commonly on the subject of whether to become a member of European Union as part of the accession process, although the EU does not require any candidate country to hold a referendum to approve membership or as part of treaty ratification. Other EU-related referendums have been held on the adoption of the euro and on participation in other EU-related policies.
The United Kingdom is the only country as an EU member state to have held referendums on continued membership of the European Union and its antecedent organisation, the European Communities. In the 1975 United Kingdom [European Communities membership referendum|first referendum in 1975], continued membership of what was then the European Communities was approved by 67.2% of voters, while in its 2016 United Kingdom [European Union membership referendum|second referendum in 2016] voters voted by 51.9% to leave the European Union, effectively reversing the result of the first referendum.
Greenland, an autonomous territory of Denmark, voted to leave the EC in a referendum in 1982 by 53% of voters.

EC enlargement of 1973

In 1972, four countries held referendums on the subject of the 1973 enlargement of the European Communities.

— 1972 French European Communities enlargement referendum, 23 April 1972, 68.3% in favour, turnout 60.5%
— a referendum to approve the Third Amendment of the Constitution of Ireland, 10 May 1972, 83.1% in favour, turnout 70.9%
— 1972 Norwegian European Communities membership referendum, 25 September 1972, 53.5% against, turnout 79%
— 1972 Danish European Communities membership referendum, 2 October 1972, 63.3% in favour, turnout 90.1%

Denmark, Ireland, and the United Kingdom were admitted as members of the EC, acceding on 1 January 1973.

United Kingdom's European Communities membership, 1975

— 1975 United Kingdom European Communities membership referendum, 5 June 1975, 67.2% in favour, turnout 64.0%

Greenland's European Communities membership, 1982

— 1982 Greenlandic European Communities membership referendum, 23 February 1982, 53.0% against

Single European Act

Two referendums were held in EU countries to permit them to ratify the Single European Act.

— 1986 Danish Single European Act referendum, 26 February 1986, 56.2% in favour, turnout 75.4%
— a referendum to approve the Tenth Amendment of the Constitution of Ireland, 26 May 1987, 69.9% in favour, turnout 44.1%

Maastricht Treaty

— 1989 Italian advisory referendum, 18 May 1989, 88.1% in favour, turnout 81.0%
— a referendum to approve the Eleventh Amendment of the Constitution of Ireland, 18 June 1992, 69.1% in favour, turnout 57.3%
— 1992 French Maastricht Treaty referendum, 20 September 1992, 51.0% in favour, turnout 69.7%
— The 1992 Danish Maastricht Treaty referendum, 2 June 1992, 50.7% against, turnout 83.1%
— The 1993 Danish Maastricht Treaty referendum, 18 May 1993, 56.7% in favour, turnout 86.5%

EU enlargement of 1995

In 1994, four countries, and one dependency, held referendums on membership of the EU, resulting in the 1995 enlargement of the European Union.

— 1994 Austrian European Union membership referendum, 12 June 1994, 66.6% in favour, turnout 82.3%
— 1994 Finnish European Union membership referendum, 16 October 1994, 56.9% in favour, turnout 70.8%
— 1994 Swedish European Union membership referendum, 13 November 1994, 52.3% in favour, turnout 83.3%
— 1994 Ålandic European Union membership referendum, 20 November 1994, 73.6% in favour, turnout 49.1%
— 1994 Norwegian European Union membership referendum, 28 November 1994, 52.2% against, turnout 89.0%

Austria, Sweden, and Finland were admitted as members of the EU, acceding on 1 January 1995.

Treaty of Amsterdam, 1998

Two countries held referendums on the ratification of the treaty of Amsterdam.

— a referendum to approve the Eighteenth Amendment of the Constitution of Ireland, 22 May 1998, 61.7% in favour, turnout 56.2%
— 1998 Danish Amsterdam Treaty referendum, 28 May 1998, 55.1% in favour, turnout 76.2%

Treaty of Nice, 2001

— a referendum to approve the Twenty-fourth Amendment of the Constitution Bill, 2001 (Ireland), 7 June 2001, 53.9% against, turnout 34.8%
— a referendum to approve the Twenty-sixth Amendment of the Constitution of Ireland, 19 October 2002, 62.9% in favour, turnout 49.5%

EU enlargement of 2004

The 2004 enlargement of the European Union involved ten candidate states, eight from Central and Eastern Europe, and the Mediterranean islands of Malta and Cyprus. In 2003, referendums on joining the EU were held in all these nations except Cyprus.

— 2003 Maltese European Union membership referendum, 8 March 2003, 53.6% in favour, turnout 90.9%
— 2003 Slovenian European Union and NATO membership referendum, 23 March 2003, 89.6% in favour, turnout 60.2%
— 2003 Hungarian European Union membership referendum, 12 April 2003, 83.8% in favour, turnout 45.6%
— 2003 Lithuanian European Union membership referendum, 10–11 May 2003, 91.9% in favour, turnout 63.4%
— 2003 Slovak European Union membership referendum, 16–17 May 2003, 93.7% in favour, turnout 52.1%
— 2003 Polish European Union membership referendum, 7–8 June 2003, 77.5% in favour, turnout 58.9%
— 2003 Czech European Union membership referendum, 13–14 June 2003, 77.3% in favour, turnout 55.2%
— 2003 Estonian European Union membership referendum, 14 September 2003, 66.8% in favour, turnout 64.1%
— 2003 Latvian European Union membership referendum, 20 September 2003, 67.5% in favour, turnout 71.5%

Since the results were in favourable in all cases, all ten candidate countries were admitted as members of the EU, acceding on 1 May 2004.

Euro

Denmark and the United Kingdom received opt-outs from the Maastricht Treaty and do not have to join the euro unless they choose to do so; Sweden has not received an opt-out, yet deliberately does not live up to the requirements for joining. Two referendums have been held on the issue, both of which rejected accession.

— 2000 Danish euro referendum, 28 September 2000, 53.2% against, turnout 87.6%
— 2003 Swedish euro referendum, 14 September 2003, 55.9% against, turnout 82.6%

European Constitution, 2005

Several member states used or intended to use referendums to ratify the Treaty establishing a Constitution for Europe.

— 2005 Spanish European Constitution referendum, 20 February 2005, 81.8% in favour, turnout 41.8%
— 2005 French European Constitution referendum, 29 May 2005, 54.7% against, turnout 69.4%
— 2005 Dutch European Constitution referendum, 1 June 2005, 61.5% against, turnout 63.3%
— 2005 Luxembourgian European Constitution referendum, 10 July 2005, 56.5% in favour, turnout 90.4%

Referendums were planned, but not held, in:

Treaty of Lisbon

Only one member state, Ireland, obliged by their constitution, decided on ratification of the Treaty of Lisbon through a referendum.

— a referendum to approve the Twenty-eighth Amendment of the Constitution Bill, 2008 (Ireland), 12 June 2008, 53.2% against, turnout 53.1%
— a referendum to approve the Twenty-eighth Amendment of the Constitution of Ireland, 2 October 2009, 67.1% in favour, turnout 59.0%

European Fiscal Compact, 2012

— a referendum to approve the Thirtieth Amendment of the Constitution of Ireland, 31 May 2012, 60.4% in favour, turnout 50.5%

EU enlargement of 2013

— 2012 Croatian European Union membership referendum, 22 January 2012, 66.7% in favour, turnout 43.5%

Croatia was admitted as a member of the EU, acceding on 1 July 2013.

San Marino membership application

A referendum was held in San Marino on whether the country should submit an application to join the European Union as a full member state.

– 2013 San Marino referendum, 20 October 2013, 50.3% in favour, turnout 43.4%

Unified Patent Court

The Unified Patent Court is a proposed court between several EU member states, that, inter alia, is to be constituted for litigation related to the European Union patent.

— 2014 Danish Unified Patent Court membership referendum, 25 May 2014, 62.5% in favour, turnout 55.9%

Greek bailout referendum, 2015

— 2015 Greek bailout referendum, 5 July 2015, 61.3% against, turnout 62.5%

Danish EU opt-out referendum, 2015

The 2015 Danish European Union opt-out referendum, 53.1% against, turnout 72.0%

Dutch Ukraine–European Union Association Agreement referendum, 2016

— 2016 Dutch [Ukraine–European Union Association Agreement referendum], 6 April 2016, 61.0% against, turnout 32.2%

United Kingdom's European Union membership, 2016

— 2016 United Kingdom European Union membership referendum, 23 June 2016, 51.9% to leave, turnout 72.2%

Hungary migrant quota referendum, 2016

— 2016 Hungarian migrant quota referendum, 2 October 2016, 98.4% against, turnout 44.0%

North Macedonia membership, 2018

– 2018 Macedonian referendum, 30 September 2018, 94.2% in favour, turnout 36.9%

Danish EU opt-out referendum, 2022

– 2022 Danish European Union opt-out referendum, 1 June 2022, 66.8% in favour, turnout 65.7%

Poland migrant quota referendum, 2023

— 2023 Polish migrant quota referendum, 15 October 2023 96.79% against, turnout 40.91%

Moldova membership goal in the constitution, 2024

– 2024 Moldovan European Union membership constitutional referendum, 20 October 2024, 50.4% in favour, turnout 51.7%

Agreements between Switzerland and the EU

— 1972: Free trade agreement with the EC, 72.5% in favour
— 1992: EEA Agreement with all EU member states and all EFTA member states as well as the European Communities, 50.3% against
— 1997: Requiring the approval of a referendum and the Cantons to launch accession negotiations with the EU, 74.1% against
— 2000: Bilateral I agreements with the EU, 67.2% in favour
— 2001: Opening negotiations for EU membership, 76.8% against
— 2005: Schengen Agreement and the Dublin Regulation, 54.6% in favour
— 2005: Freedom of movement for workers, to include 10 new EU members, 56.0% in favour
— 2006: Cohesion contribution of one billion for the ten new member states of the EU, 53.4% in favour
— 2009: Freedom of movement for workers, to include two new EU members, 59.6% in favour
— 2009: Introduction of biometric passports, as required by the Schengen acquis, 50.1% in favour
— 2014: Freedom of movement for workers to be reduced, 50.3% in favour
— 2020: Termination of the 1999 Agreement on the Free Movement of Persons, 61.7% against

Future referendums

Joining the EU

Countries which seek to join the European Union in the future may hold a referendum as part of the accession process.
Iceland, which submitted an application for EU membership in 2009 but subsequently suspended negotiations after a change in government, plans to hold a referendum on resuming negotiations by 2027.
In Armenia, a hearing in the National Assembly on 21 June 2024 was organized by the United Platform of Democratic Forces, to consider holding a referendum on the submission of an application for EU membership. On 27 June 2024, the president of the National Assembly, Alen Simonyan, confirmed that Armenia's leadership wants the country to join the EU and that it will hold a referendum in the near future. Simonyan stated "Our society has made a decision to be part of the European Union" and "I think that sometime in the near future we will have this referendum and I am sure that our people will say yes". On 25 October 2024, the UPDF announced that over 60,000 signatures had been collected in a nation-wide petition called Eurovote, in which signatures were gathered in support of holding a referendum on Armenia's EU membership.
The constitution of France requires that any future treaty on the accession of new EU member states be approved in a referendum. Politicians in other existing member states have proposed referendums in their states, particularly with respect to the accession of Turkey.

Withdrawal from the EU

Similarly, there have been proposals by eurosceptic parties and movements across the EU on holding referendums on withdrawing from the EU, since the United Kingdom voted in favour of withdrawing in a 2016 referendum.

Unified Patent Court

Ratification by Ireland of the agreement establishing the Unified Patent Court requires approval in a referendum, which was originally planned for 2024 but subsequently postponed.

Association Agreement

Andorra is expected to hold a referendum on the Association Agreement it has negotiated with the EU.