Sejong has a population of 351,007 as of 2020 and covers a geographic area of 465.23 km2 (179.63 sq mi), making it the least-populous and smallest first-level administrative division in South Korea.

The goal was to reduce the influence and dominance of Seoul on national governance and economics, whilst promoting the regional development of other areas of the country.

In October 2004, the Constitutional Court dealt a setback to President Roh's plans, ruling that the capital must remain in Seoul in response to a complaint filed by the main opposition, the conservative Grand National Party.

[6] When the Grand National Party retook the presidential office in 2008, then-President Lee Myung-bak opposed the idea of moving government agencies, claiming that it would hurt Seoul's global competitiveness and result in inefficiency.

[6] Following Lee's directions, plans were made to make Sejong an industrial, science and education hub instead.

Defeat in the mid-2010 local elections forced Lee to present his proposal to the National Assembly where it was voted down.

Sejong uses its new development to market itself as an alternative to Seoul, offering luxury living at a fraction of the cost.

It boasts shiny state-of-the-art condominiums, ample public green space and smart and sustainable city tech, like automated trash collection and zero-waste food disposal, electric car charging and sharing stations, solar-powered buildings, interactive digital signage, closed-circuit television security and fine dust emergency alerts.

Sejong is divided into 14 haengjeong-dong (administrative neighborhoods), 1 eup (town) and 9 myeon (townships).

* Note: there are no Hanja for Hansol, Dodam, Areum, Goun, Boram, Saerom, Sodam, Dajeong, Eojin, or Haemil as they are native Korean words.

[25] Government Complex Sejong includes the head offices of: Several MOLIT agencies, the Korea Office of Civil Aviation (KOCA), the Korean Maritime Safety Tribunal (KMST), and the Aviation and Railway Accident Investigation Board (ARAIB), have their headquarters in Government Complex Sejong.

There has also been some debate concerning opening another KTX station within the new Sejong City close to the bus terminal to the south.

In April 2019, a feasibility study was completed and approved an extension of Daejeon Metro Line 1 from Banseok station in Daejeon, accessing the southern bus terminal in Sejong, and ending at the Government Complex Sejong.