Total population299,492people
Households147,190households
Average age45.1yrs
Sex ratioMale141,003peopleFemale158,489people47.1%52.9%
Population change
Change over time
4-year trendUnit: people
306,253 in 2022299,492 in 2026
Down 2.2% over the past 4 years.
Migration
As of August 2026Monthly Overview
Moved in3,476people
Moved out3,495people
Net migrationβ19people
Net migration by month
Unit: people
Net inflowNet outflow
Top origins
Unit: people
| Region | Moved in |
|---|---|
| Mapo-gu | 292 |
| Eunpyeong-gu | 267 |
| Goyang-si, Gyeonggi | 156 |
| Jongno-gu | 91 |
| Gwanak-gu | 85 |
Top destinations
Unit: people
| Region | Moved out |
|---|---|
| Eunpyeong-gu | 316 |
| Mapo-gu | 233 |
| Goyang-si, Gyeonggi | 212 |
| Seocho-gu | 102 |
| Jongno-gu | 87 |
Outflows exceeded inflows in 10 of the past 12 months, for a net loss of 1,391.
Population structure
Population by age
As of September 2026Population by age and sex
Unit: people
Male 141,003Female 158,489
Age structure
Unit: %
Youth 8.6%Working age 70.2%Seniors 21.3%
50s is the largest group, at 47,259 people.
Population ranking
Population by region
As of September 2026- YoungestDaehyeon-dong34.5 yrs
- OldestOkcheon-dong51.3 yrs
| Region | Share | ||
|---|---|---|---|
| Hongje-dong | 53,058 | 17.7% | 47.5 yrs |
| Hongeun-dong | 50,353 | 16.8% | 46.9 yrs |
| Bukgajwa-dong | 46,495 | 15.5% | 47 yrs |
| Namgajwa-dong | 45,564 | 15.2% | 42.7 yrs |
| Yeonhui-dong | 32,954 | 11% | 44.4 yrs |
| Bugahyeon-dong | 26,651 | 8.9% | 44.3 yrs |
| Changcheon-dong | 10,812 | 3.6% | 38.5 yrs |
| Daehyeon-dong | 6,970 | 2.3% | 34.5 yrs |
| Hyeonjeo-dong | 4,915 | 1.6% | 48.1 yrs |
| Chungjeongno3-ga | 4,702 | 1.6% | 45.8 yrs |
| Cheonyeon-dong | 4,434 | 1.5% | 45.1 yrs |
| Yeongcheon-dong | 3,219 | 1.1% | 46.1 yrs |
| Naengcheon-dong | 2,983 | 1% | 44.8 yrs |
| Daesin-dong | 1,572 | 0.5% | 36.6 yrs |
| Chungjeongno2-ga | 1,140 | 0.4% | 45.5 yrs |
| Hap-dong | 1,104 | 0.4% | 40.4 yrs |
| Okcheon-dong | 914 | 0.3% | 51.3 yrs |
| Sinchon-dong | 884 | 0.3% | 38.5 yrs |
| Migeun-dong | 425 | 0.1% | 49.8 yrs |
| Bongwon-dong | 343 | 0.1% | 49.1 yrs |
The top three areas hold 50.1% of the population of Seodaemun-gu, Seoul.
Want to explore Seodaemun-gu's demographics in more detail?See more Seodaemun-gu statistics on GData
Frequently asked questionsβ
Seodaemun-gu, Seoul has 299,492 residents as of September 2026., 1,604 fewer than a year earlier.
Hongje-dong, home to 53,058 residents (17.7% of Seodaemun-gu, Seoul).
It is 45.1 as of September 2026., 0.6 years below the national average of 45.7. Among its neighborhoods, Daehyeon-dong is youngest at 34.5 and Okcheon-dong oldest at 51.3.
It fell 2.2% over 4 years, from 306,253 in 2022 to 299,492 in September 2026.
As of August 2026, the most people moved in from Mapo-gu (292) and the most moved out to Eunpyeong-gu (316). Outflows exceeded inflows in 10 of the past 12 months, for a net loss of 1,391.
This is resident registration data from Korea's Ministry of the Interior and Safety. Figures are as of the end of September 2026 and are updated monthly. The data is open under KOGL Type 1.
Resident registration counts people at their registered address. The census counts them where they actually live. The gap is widest in university towns and industrial areas, where many people never change their registered address.
Sources π
- Resident registration data, Ministry of the Interior and SafetyKOGL Type 1 Β· as of September 2026 Β· updated monthly
- Internal Migration Statistics, Statistics Korea (KOSIS)KOGL Type 1 Β· as of August 2026 Β· updated monthly