South Korea maintains diplomatic relations with every United Nations member state except for North Korea. The country is a member of the United Nations, WTO, OECD/DAC, ASEAN Plus Three, East Asia Summit (EAS), and G-20. It is also a founding member of Asia-Pacific Economic Cooperation (APEC) and the East Asia Summit.

South Korea has been a member of the United Nations since 1991, when it became a member state at the same time as North Korea. The country has also hosted major international events such as the 1988 Summer Olympics and 2002 World Cup Football Tournament (2002 FIFA World Cup co-hosted with Japan) and the 2011 IAAF World Championships Daegu South Korea. Furthermore, South Korea had hosted the 2018 Winter Olympics which took place in Pyeongchang from 9 to 25 February.

The diplomacy of South Korea is handled by the Ministry of Foreign Affairs (MOFA). On 1 January 2007, South Korean Foreign Minister Ban Ki-moon assumed the post of UN Secretary-General, serving in that post until 31 December 2016. The country held the 2023 South Korea-Pacific Islands Summit, the 2024 South Korea-Africa Summit and the 2026 South Korea-Central Asia Summit to deepen cooperation with developing countries.

In June 2024, South Korea introduced the "K-Silk Road Initiative," a comprehensive strategy to deepen cooperation with Central Asian nations in trade, investment, infrastructure, energy, and digital connectivity. The inaugural Korea-Central Asia Summit is scheduled to be held in Seoul on September 16–17, 2026, bringing together the leaders of South Korea and the five Central Asian states.

International organization participation For economy and finance: Club de Paris, IFC, IBRD, IDA, OECD, MIGA, ICSID, ADB, AIIB, AfDB, AfDF, EBRD, IADB, MIF, CFC, CABEI, BIS, South East Asian Central Banks, Executives' Meeting of East Asia and Pacific Central Banks, FSB, World Bank (MIGA), EBRD, ITC, WTO, IMO, IMF, WBG, IPEF, APEC For energy and chemical: IEA, IAEA, OPCW, CTBTO For security: NATO (Global Partner), MIKTA, OSCE For food: IGA, WFP, UNICEF, FAO, IFAD, For culture: BIE, UNESCO, UNWTO, IOM, AIPH (Partner), IOC, OCA, IPC For justice: ICAO, ICPO For support of developing countries: UNDP, DAC Other: UN, G-20, IPU, UNEP, ILO, ITU, UNIDO, UPU, WHO, WIPO, WMO, GGGI

Foreign policy

South Korea's Indo-Pacific strategy is a comprehensive strategy that encompasses the economic and security spheres of Indo-Pacific countries. Announcing the strategy, the country said, "While strengthening the rules-based International order, which is conducive to a stable and prosperous Indo-Pacific, we will work towards a regional order that enables a diverse set of nations to cooperate and prosper together."

Free trade agreements

South Korea has the following trade agreements: South Korea-ASEAN (Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, Vietnam) FTA South Korea-Australia FTA South Korea-Canada CKFTA FTA South Korea Central America (Costa Rica, El Salvador, Honduras, Nicaragua, Panama) FTA South Korea-Chile FTA South Korea-China FTA South Korea-Colombia FTA South Korea-EFTA (Iceland, Lichtenstein, Norway, Switzerland) FTA South Korea-EU (Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, UK) FTA South Korea-India CEPA FTA South Korea-Indonesia South Korea-Israel South Korea-New Zealand FTA South Korea-Peru FTA South Korea-RCEP (Australia, Brunei, Cambodia, China, Indonesia, Japan, South Korea, Laos, Malaysia, Myanmar, New Zealand, the Philippines, Singapore, Thailand, and Vietnam) South Korea-Singapore FTA South Korea-Turkey FTA South Korea-United Kingdom (KUKFTA) South Korea-United States of America (KORUS FTA) South Korea-Vietnam FTA

As of late 2021 states of GCC (Gulf Cooperation Council—Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates), Israel, Japan, Malaysia, MERCOSUR (Southern Common Market—Mercado comun del sur), Mexico, Mongolia, RCEP (Asian 10 Countries, Korea, China, Japan, Australia, New Zealand, India), Russia (BEPA), SACU (South Asia Cooperation Union) and South Korea-China-Japan are in negotiations about the FTA with South Korea. On 22 November 2023, South Korea and the United Kingdom opened up negotiations for a new Free Trade Agreement, to replace the current continuity trade agreement.

Asia China (PRC)

Active South Korean-Chinese people-to-people contacts have been encouraged. Academics, journalists and particularly families divided between South Korea and the People's Republic of China (PRC) were able to exchange visits freely in the late 1980s. Nearly 2 million ethnic Koreans, especially in the Yanbian Korean Autonomous Prefecture in Jilin Province of Northeast China, have interacted with South Koreans.

Trade between the two countries continued to increase nonetheless, Furthermore, China has attempted to mediate between North Korea and the United States, and between North Korea and Japan. China also initiated and promoted tripartite talks between North Korea, South Korea and the U.S.

South Korea had long been an ally of Taiwan. Diplomatic ties between Seoul and Taipei were nevertheless severed in 1992. Formal diplomatic relations were established between Seoul and Beijing on 24 August 1992.

In 2004 the PRC government began the Northeast Project, sparking a massive uproar in South Korea when the project was widely publicized.

After the KORUS FTA (United States-South Korea Free Trade Agreement) was finalized on 30 June 2007, the Chinese government has immediately begun seeking an FTA agreement with South Korea. The FTA between South Korea and China are under discussion. South Korea has been running a trade surplus with China which hit a record US$32.5 billion in 2009.

Taiwan (ROC)

On 23 August 1992, the government of the Republic of China (by then only in control of the island of Taiwan and a few outlying areas) severed diplomatic relations with South Korea in advance of its announcement of formal recognition of the People's Republic of China based in Beijing. The Yonhap News said in 2002 that since then relations between the two governments have been "in a rut".

Japan

The relation between South Korea and Japan has both political conflicts and economic intimacies. Examples of conflicts include the East sea naming dispute, visits by successive Japanese Prime Ministers to the Yasukuni Shrine and the disputed ownership of Dokdo of the island Korea.

On 18 January 1952, The first president of South Korea Syngman Rhee declared that the vicinity of Dokdo was a territory of South Korea (Syngman Rhee line). Subsequently, some 3,000 Japanese fishermen who conducted fishery operations in this vicinity were captured. This incident, called the Dai Ichi Daihoumaru Ship case strained relations between South Korea and Japan.

22 June 1965, The president in South Korea Park Chung Hee concluded the Treaty on Basic Relations between Japan and South Korea As a result, Japan considered South Korea to be the legitimate successor of its rule over the Korean Peninsula.

South Korea's trade with Japan was US$892.1 million in 2008, with a surplus of nearly US$327.1 million on the Japanese side. Japanese and South Koreans firms often had interdependent relations, which gave Japan advantages in South Korea's growing market.

In 1996 FIFA announced that the South Korea-Japan would jointly host the 2002 FIFA World Cup. The next few years would see leaders of both countries meet to warm relations in preparations for the games. The year 2005 was designated as the "Japan-South Korea Friendship Year". However, the Liancourt Rocks controversy erupted again when Japan's Shimane Prefecture declared "Takeshima Day", inciting mass demonstrations in South Korea.

Japan calls South Korea a partner in its diplomatic charter, and South Korean President Yoon Suk Yeol also said, "Korea and Japan are now partners who share universal values and pursue common interests."

Mongolia

Both countries established diplomatic relations on 26 March 1990. South Korea has an embassy in Ulaanbaatar, Mongolia. Mongolia has an embassy in Seoul.

Philippines

Since the establishment of diplomatic ties on 3 March 1949, the relationship between the Philippines and South Korea has flourished. The Philippines was one of the first countries that extended diplomatic recognition to South Korea. This was cemented with the Philippine government's deployment of the Philippine Expeditionary Force to Korea (PEFTOK) to help South Korea against the invasion of the communist North during the Korean War in the 1950s. After the war, the Philippines provided development assistance to South Korea and helped the country rebuild itself.

Since then, the Philippines's relations with South Korea have evolved with South Korea becoming one of the Philippines's most important bilateral partners aside from the United States, China and Japan. The Philippines's government seeks to cultivate strategic ties with South Korea given its increasing presence in the country. In the coming years, the Philippines anticipates to benefit from exploring unprecedented opportunities from South Korea that shall contribute significantly to the country's trade and economy, defense and security, and society and culture.

Vietnam

The relationship between these two Sinosphere countries is usually described as "from enemies to friends". Despite the two states' hostile positions in the Vietnam War and South Korean war crimes and atrocities in the Vietnam War, which still causes lingering controversies between the two states, both countries have still become each other's most important trade partner throughout their relationship. South Korea is the third biggest trade partner of Vietnam while also being the second-biggest ODA provider and the biggest foreign direct investor to Vietnam; meanwhile, Vietnam is the third-biggest trade partner of South Korea and it is also hosting many important factories and facilities of South Korea's biggest conglomerate such as Samsung and LG.

In December 2022, the two nations have elevated their ties to comprehensive strategic partnership – technically the highest level of bilateral relationship that is designated by the Vietnamese side. Both countries have aimed to raise their two-way trade to 100 billion U.S. dollars in 2023 and expected to reach 150 billion by the end of this decade. Besides major economic ties and cooperations, South Korea and Vietnam also plan to further cooperate in politics, cultural exchange, resources exploitation, national security as well as in the defense sectors. Both countries share core benefits, concerns, and support to each other in issues related to the security of the region, noticeably Vietnamese support towards South Korea's effort in denuclearization of the Korean Peninsula (mentioning North Korea) and South Korea's support on Vietnam's attitude towards the stability and freedom of navigation of the South China Sea. Vietnam is also an important partner of South Korea to exercise its Indo-Pacific strategy and the insight to strengthen South Korea's relationship with the Association of Southeast Asian Nations. It is said that Vietnam can be a "bridge" or "ambassador" representing South Korea's influence to the Southeast Asia region.

In the state visit of the President of Vietnam to South Korea in December 2022, South Korean President Yoon Suk-yeol has honored Vietnamese President Nguyễn Xuân Phúc as "my very first national guest" (referring the fact that his Vietnamese counterpart was the first head of state to visit South Korea during his terms), and also saying that the people of Vietnam and South Korea are "close brothers".

North Korea