South Korean Politics
South Korea — formally the Republic of Korea — is a presidential democracy. The system dates from the 1987 constitution that ended decades of military rule and opened what Koreans call the “Sixth Republic”. A directly elected president serves a single five-year term and cannot run again; a separate National Assembly is elected every four years. Power swings between two big camps: a liberal bloc — today the Democratic Party — and a conservative one, today the People Power Party.
It is a young democracy with deep roots in street protest, and it has tested its institutions hard. Two presidents have been impeached and removed: Park Geun-hye, ousted in 2017 over a corruption scandal, and Yoon Suk-yeol, who declared martial law in December 2024, was overturned by the Assembly within hours, and was removed by the Constitutional Court in April 2025. The charts below show how the Assembly and the presidency have looked across the democratic era.
The National Assembly, 2004–2024
Each column is one legislative election; the stack shows how the 300 seats in the National Assembly split between the liberal (Democratic) bloc, the conservative bloc, and the minor parties. Korean parties rename and merge almost every cycle, so they are grouped here by camp rather than by their party-of-the-day name. Switch to vote share for the combined constituency-and-list vote. The grey line is turnout. Tap a column for the result.
2004–2024 · seats — tap a column
Seats of 300 (299 before 2012); the dashed line marks the 151 needed for a majority. Parties are grouped by orientation because their names change so often — the Uri Party, Democratic United, Minjoo and today's Democratic Party are all the liberal bloc; the Grand National, Saenuri, United Future and today's People Power Party the conservative one. From 2020 each camp's totals include its proportional “satellite” list party. Sources are listed at the foot of the page. Last reviewed June 2026.
The presidents, 1987–2025
Since the 1987 democratic transition South Korea has had nine presidents, each limited to a single five-year term. The bands are the presidents; the line traces either the winner's vote share or turnout at each presidential election. Tap a band for the leader and the era.
1987–2025 · the presidents — tap a band
Bands are the president of the day; presidents are barred from a second term, so the office turns over often. Vote shares are the winner's share in a single-round, first-past-the-post election (there is no run-off), which is why several presidents took office with well under half the vote. Park Geun-hye and Yoon Suk-yeol were both removed by impeachment before their terms ran out. Sources are below.
How power works
South Korea concentrates considerable power in a directly elected president, held in check by a separate legislature and an unusually activist Constitutional Court — which has now twice removed a sitting president. It helps to look at the main institutions in turn.
The president
The dominant office: head of state and of government, directly elected for a single five-year term with no re-election. The president commands the armed forces, sets foreign policy, and appoints the prime minister (with the Assembly's consent) and the cabinet. The one-term limit — a deliberate safeguard against the strongman past — means every president is a lame duck from the day they take office and cannot build a lasting personal machine.
The prime minister and cabinet
The prime minister, nominated by the president and approved by the Assembly, supervises the cabinet and the ministries. The post is clearly subordinate to the president — more chief operating officer than rival power centre.
The National Assembly
A single elected chamber of 300 members, chosen every four years — most from local districts and the rest by proportional party list. It passes laws and the budget, confirms some appointments, and can impeach the president and other officials by a two-thirds vote; the Constitutional Court then decides whether the removal stands.
The Constitutional Court and judiciary
A nine-member Constitutional Court rules on the constitutionality of laws and on impeachments. It confirmed Park Geun-hye's removal in 2017 and Yoon Suk-yeol's in 2025, which makes it one of the most consequential institutions in the country. A separate Supreme Court sits atop the ordinary court system.
At a glance
The main institutions, roughly from the top down — “chosen by” describes how each is selected.
| Body | Role | Chosen by |
|---|---|---|
| President | Head of state & government; foreign affairs, armed forces | Direct election (single 5-year term) |
| Prime Minister | Supervises the cabinet and ministries | President, with Assembly consent |
| National Assembly | Single-chamber legislature; laws, budget, impeachment | Direct election (300 seats, 4-year term) |
| Constitutional Court | Rules on laws and on impeachments | 9 justices (president, Assembly, Chief Justice) |
| Supreme Court | Highest court for ordinary cases | Chief Justice & justices, via the Assembly |
The parties
Korean parties are notoriously fluid — they merge, split and rebrand almost every cycle — but two broad camps have endured, with a scattering of smaller parties around them.
Democratic Party of Korea
The main liberal, centre-left party, descended through a string of names (Uri, Democratic United, Minjoo) from the pro-democracy movement. It is strongest in the south-west — the Jeolla region — and among younger urban voters, favours engagement with the North and a larger welfare state, and is led by Lee Jae-myung, who won the 2025 presidency.
People Power Party
The main conservative party, heir to the Grand National and Saenuri parties and, further back, to the ruling parties of the authoritarian era. It is strongest in the south-east (the Gyeongsang region), pro-business and firmly pro-US-alliance, and generally hawkish on North Korea. It governed under Yoon Suk-yeol until his removal in 2025.
Rebuilding Korea and the minor parties
A shifting cast of smaller parties win seats, especially on the proportional list. The Rebuilding Korea Party, led by Cho Kuk, took a dozen seats in 2024; the progressive Justice Party, the splinter Reform Party and others come and go. In 2016 the centrist People's Party briefly broke the two-party mould before fading.
Sources & notes
A note on how this page was made: the charts, the data behind them, and some of the drafting were put together with the help of AI tools. I've checked the headline figures — National Assembly seat totals and presidential vote shares — against the public record, but any mistakes are mine; if you spot one, please let me know. Because Korean parties rename and merge so frequently, the Assembly chart groups them by camp rather than tracking every party name.
- Election results. Official National Assembly seat totals and presidential vote shares from South Korea's National Election Commission and summarised on Wikipedia.
- Presidents & institutions. The succession of presidents and the structure of the Sixth Republic from the standard public record.
- Recent events. The December 2024 martial-law episode and the 2025 impeachment, removal and snap presidential election, as reported at the time.
Some of the figures in the charts and tables on this page were compiled with the help of AI tools and may contain errors or be out of date. They are shared in good faith for general interest only — not as professional, financial, investment or purchasing advice — and should be checked against the cited primary sources before you rely on them.