Membership of the United Nations Security Council is held by the five permanent members and ten elected, non-permanent members. Being elected requires a two-thirds majority vote from the United Nations General Assembly. Elected members hold their place on the council for a two-year term, with five seats contested in even years and five seats contested in odd years. An outgoing member cannot be immediately re-elected. Elections usually begin in October for a term starting January 1. Because of the two-thirds majority requirement, it is possible for two evenly matched candidates to deadlock with approximately half the vote each, sometimes needing weeks of negotiations to resolve. Non-permanent seats are distributed geographically, with a certain number of seats allocated to each of the five United Nations Regional Groups.

Current membership

Regional Groups

The ten non-permanent seats have the following distribution: In addition, one of the five African/Asian seats is an Arab country, alternating between the two groups. This rule was added in 1967 for it to be applied beginning with 1968.

• The representative of Arab nations alternates between these two spaces. The odd/even distribution was effectively decided by the January 1946 and 1965 elections (the first ever election, and the first election after the expansion of seats). For each of the six and four members in the newly created seats, the UN General Assembly voted to grant either a 1-year or 2-year term.

{{Legend|#339900|Asia-Pacific Group}} {{Legend|#cc0000|Eastern European Group}} {{Legend|#cc3399|Latin American and Caribbean Group (GRULAC)}} {{Legend|#cc9900|Western European and Others Group}} {{Legend|#000000|UN member not in any voting group}} {{Legend|#00ff00|Observer states}} {{Legend|#c0c0c0|Non-UN state or territory|undefined | upload.wikimedia.org/wikipedia/commons/4/4a/UN///regional///groups.svg]

Previous Security Council composition

From 1946 to 1965, the Security Council had six non-permanent members. Due to a lack of African and Asian member states, the seats had the following distribution: As decolonization increased the number of Asian and African member states without a group, they began to contest other seats: Ivory Coast substituted a member of the Commonwealth in 1964–1965, the Eastern European seat regularly included Asian countries from 1956, Liberia took the place of a Western European country in 1961, and Mali successfully contested the Middle Eastern seat in December 1964 (the Security Council would be expanded before Mali's term began). An amendment to the UN Charter ratified in 1965 increased the number of non-permanent seats to 10, and the Regional Groups were formalized. The amendment effectively created three African seats and one Asian seat (if treating the Commonwealth seat as a WEOG seat and the Middle Eastern seat as an Asian seat).

Membership by year

Permanent

Non-permanent (1946–1965)

Non-permanent (1966–present)

The African Group uses an internal rotation system to distribute seats based on its subregions: Aside from the Asia-Pacific Group also allocating an Arab nation seat every four years (in even years not divisible by 4), other regional groups do not have their own subregional rotation systems. The Arab nation seat is starred below. The Western European and Others Group in part contains three caucusing subgroups (Benelux, the Nordic countries, and CANZ), whose candidates informally coordinate with each other. While this has not resulted in a stable rotation system, it effectively guarantees that both seats will never be occupied by a single subgroup at the same time.

List by number of years as Security Council member

This list contains the 138 United Nations member states so far elected to the United Nations Security Council, including the five permanent members, all listed by number of years each country has so far spent on the UNSC. Of all the members, 6 have so far ceased to exist, leaving the list with 132 modern nations. These, combined with the 61 modern nations that have never been elected to the UNSC to date (see Non-members, below), make up the 193 current members of the UN. Years on the Security Council,, including current year where relevant : {{Legend|#ffb6c1|Indicates permanent member}} {{Legend|#cdf|Indicates current elected member (2024)}} {{Legend|#fafad2|Indicates former United Nations member}}

Future membership

The following countries have made known their applications for future United Nations Security Council membership:

Non-members

The United Nations Charter requires that elections to the Security Council take into account "the contribution of Members...to the maintenance of international peace and security". As a result, many nations, small or otherwise, have never been on the Security Council. The following list is a summary of all countries, currently 61 modern nations and three historical ones that have never been a member of the United Nations Security Council. The three historical UN members listed are Tanganyika, Zanzibar, and Serbia and Montenegro. {{Legend|#fafad2|Indicates former United Nations member}}