As of May 2026, the population of Mongolia is 3.6 million. The number of inhabitants has increased by 41 thousand in the last year, representing a growth of 1.20%. The median age of the population has increased in recent years, rising from 26 years in 2016 to 27.4 years in 2026. Currently, life expectancy at birth is 73.7 years and population density is 2.3 inhabitants per square kilometer.
The population growth rate of Mongolia peaked in 1960, reaching around 3.43% annually, but has since declined to approximately 1.16% in 2026. The annual increase in the number of people has also decreased from a peak of around 68.81 thousand in 2018 to nearly 41.49 thousand in 2026.
In Mongolia, life expectancy at birth has been increasing, with the indicator rising from 65.5 years in 2006 to 73.7 years in 2026, representing an increase of more than 8 years over the past 2 decades.
The cities of Mongolia are small, with the 5 most populated adding up to around 1.1 million inhabitants. The most populous city is Ulan Bator, Ulaanbaatar, con una diferencia significativa sobre las demás, alcanzando approximately 844.8 thousand inhabitants. It is followed by Erdenet, Orhon with 97.8 thousand and Darhan, Darhan Uul with 83.9 thousand.
These are the 20 most populous cities in Mongolia:
| # | City | Population |
|---|---|---|
| 1 | Ulan Bator, Ulaanbaatar | 844,818 |
| 2 | Erdenet, Orhon | 97,814 |
| 3 | Darhan, Darhan Uul | 83,883 |
| 4 | Choibalsan, East Aimak | 44,835 |
| 5 | Nalayh, Ulaanbaatar | 39,579 |
| 6 | Mörön, Khövsgöl Province | 39,404 |
| 7 | Bayanhongor, Bayankhongor | 30,931 |
| 8 | Ulaangom, Uvs Province | 30,092 |
| 9 | Khovd, Hovd | 29,800 |
| 10 | Arvayheer, Övörhangay | 29,420 |
| # | City | Population |
|---|---|---|
| 11 | Ölgii, Bayan-Ölgii Province | 28,400 |
| 12 | Bogd, Övörhangay | 27,924 |
| 13 | Dalandzadgad, Ömnögovĭ | 24,863 |
| 14 | Undurkhaan, Hentiy | 22,741 |
| 15 | Sühbaatar, Selenge Province | 22,741 |
| 16 | Tsetserleg, Arkhangai Province | 21,620 |
| 17 | Saynshand, East Gobi Aymag | 19,891 |
| 18 | Dzüünharaa, Selenge Province | 18,830 |
| 19 | Baruun-Urt, Sühbaatar | 18,190 |
| 20 | Altai, Govi-Altai Province | 17,617 |