Seosan: population and official figures
In depth
- Health in Seosan: The Ministry of Health and Welfare estimates 3,943 people aged 65 or over in Seosan had dementia in 2025, or 10.0% of the 39,568 people in that age group (above the national figure of 9.1%). The figure is an estimate that applies national age-and-sex rates from the 2023 dementia survey to the local population. Seosan ranks 3rd highest estimated dementia rate of 36 South Korean cities covered on this site.
- Poverty and living standards in Seosan: 6,805 people in Seosan in 5,154 households were eligible for the basic livelihood security programme (customised benefits) in December 2025, or 39.9 for every 1,000 registered residents (South Korea: 55.4). Eligible means entitled to benefits, whether or not they were paid out. Seosan ranks 5th lowest share eligible of 36 South Korean cities covered on this site.
What is the population of Seosan?
Seosan had 170,634 registered residents on 30 September 2026, according to the Ministry of the Interior and Safety resident registration count across 15 neighbourhoods (eup, myeon and dong). Seosan holds 0.33% of the 51.08 million people registered in South Korea. Seosan ranks 10th smallest of 36 South Korean cities covered on this site.
Source: Ministry of the Interior and Safety (Republic of Korea) · saved copyWhat percentage of people in Seosan are over 65?
24.8% of the registered residents of Seosan were aged 65 or over on 30 September 2026 (South Korea: 22.1%), and 10.6% were under 15 (South Korea: 10.0%). Working-age people (15 to 64) made up 64.6%. Seosan ranks 16th oldest by share of residents aged 65+ of 36 South Korean cities covered on this site.
Source: Ministry of the Interior and Safety (Republic of Korea) · saved copyWhat is the average age in Seosan?
The average age of registered residents of Seosan was 47.2 years on 30 September 2026, close to the national figure of 45.8 years. Seosan ranks 15th oldest of 36 South Korean cities covered on this site.
Source: Ministry of the Interior and Safety (Republic of Korea) · saved copyAre there more men or women in Seosan?
Seosan had 110 men for every 100 women among registered residents on 30 September 2026 (89,357 men and 81,277 women; South Korea: 99). Seosan ranks 3rd most male of 36 South Korean cities covered on this site.
Source: Ministry of the Interior and Safety (Republic of Korea) · saved copyHow many elderly people live in Seosan?
42,367 registered residents of Seosan were aged 65 or over on 30 September 2026, and 6,030 of them were aged 85 or over.
Source: Ministry of the Interior and Safety (Republic of Korea) · saved copyWho runs Seosan?
In South Korea, cities and towns are run by upper-level local governments: Mayor or governor and council directly elected for four years; superintendent of education also directly elected. Regional planning, roads, transport, police support (autonomous police), education (via the education office).
How local power works in South Korea
Cities of a similar size in South Korea
- Sejong 390,585
- Asan 366,594
- Yangsan 360,962
- Jinju 333,850
- Iksan 266,458
- Gyeongsan 262,849
- Gunsan 255,575
- Gyeongju 242,405
- Geoje 228,629
- Icheon 227,007
- Seogwipo 178,294
- Dangjin 172,300
- Andong 151,366
- Gimcheon 132,274
- Tongyeong 115,838
- Sacheon 107,862
Up a level: all cities in South Korea · South Korea · government and power
Sources
- Ministry of Health and Welfare (Republic of Korea): Dementia status by city, county and district, 2016-2025 (open file on the Public Data Portal), read 30 October 2026 · saved copy (SHA-256 85455041c38b…)
- Health Insurance Review and Assessment Service (HIRA): Diabetes treatment statistics by city, county and district, 2025 (open file on the Public Data Portal), read 30 October 2026 · saved copy (SHA-256 547bd6a4555a…)
- Health Insurance Review and Assessment Service (HIRA): Health-care institutions registered with the insurance service, as of 31 December 2025 (open file on the Public Data Portal), read 30 October 2026 · saved copy (SHA-256 bb10d7930007…)
- Ministry of the Interior and Safety (Republic of Korea): Ministry of the Interior and Safety: resident registration population by sex and age, by neighbourhood, 30 September 2026 (open file on the Public Data Portal), read 30 October 2026 · saved copy (SHA-256 23a269d2fd75…)
- Korea Road Traffic Authority: Road traffic accident statistics by city, county and district, 2025 (open file on the Public Data Portal), read 30 October 2026 · saved copy (SHA-256 077c48b46c23…)
- Korea Social Security Information Service: People eligible for welfare programmes by city, county and district, December 2025 (open file on the Public Data Portal), read 30 October 2026 · saved copy (SHA-256 157ececacb6e…)
Each saved copy is the file exactly as downloaded, kept so the figures can be checked even if the source changes. Report an error.