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Onitsha, 
Nigeria
5,627,706 people lived in Onitsha in 2025. It is the 69th largest of the world's 12,138 cities, and the 2nd largest in Nigeria.
That figure counts the whole built-up area, not the area Onitsha governs, so it may be far from the number the city publishes about itself. How the UN measures a city.
Verified 2026-09-30 · 73 canaries
People · every five years · 1975 to 2050
How Onitsha grew
Where Onitsha had 10 people in 1975, it had 74.4 in 2025.
On the UN's projection it will have 8.7 million people in 2050. It passed five million people between 2020 and 2025.
projected (after 2025) · how sure the UN is: high moderate low
How to read this: one column every five years, 1975 to 2050; its height is the number of people. Hatched columns are the UN's projection. The thin strip beneath says how sure the UN is of each figure: the stronger the colour, the surer. A blank means the place was not on the UN's list of cities that year.
People · your family's years · 1975 to 2050
Onitsha through your family’s years
Put in the years your family were born. You’ll see how many people lived in Onitsha in each of those years, and when each of them turned 30.
Nigeria · every city · 2025
Where it is
How to read this: Nigeria and its 457 cities in 2025, each a dot whose area is its number of people (the largest is Lagos). Onitsha is ringed, in colour; the other cities are grey. Neighbouring countries are outlines.
Area and built-up land · km²
How much land it covers
In 2025, Onitsha covered 1,093 km², and buildings, roads and other built-up land covered 216 km² of it. That is 38 m² of built-up land for each person, about a square 6 by 6 metres. Since 1975, its built-up land has grown to 5 times its size, and its people are 7.4 times as many.
How to read this: pale is the whole of the city's land; the stronger square inside it is what is actually built on. The three are drawn to the same scale, so a larger square really is more land, and hatching means the year is the UN's projection rather than a count.
Of every 100 people in Nigeria
Its share of Nigeria
Of every 100 people in Nigeria in 2025, 2 lived in Onitsha, which is 5.6 million people.
How to read this: 100 squares, one for every 100th person in Nigeria; the coloured squares live in Onitsha. The grey rest live in other cities, in towns or in the countryside.
Ranked by people · 2025
Cities of a similar size
In the world, 2025
- 65 Nairobi Kenya6,134,334
- 66 Kozhikode India6,123,872
- 67 Shenyang China5,702,638
- 68 Kabul Afghanistan5,635,737
- 69 Onitsha5,627,706
- 70 Yangon Myanmar5,618,303
- 71 Accra Ghana5,592,780
- 72 Madrid Spain5,583,601
- 73 Faisalabad Pakistan5,566,382
In Nigeria, 2025
- 26 Lagos12,791,699
- 69 Onitsha5,627,706
- 89 Kano4,840,280
- 121 Owerri3,833,343
- 123 Ibadan3,720,721
- 211 Port Harcourt2,341,445
- 266 Kaduna1,890,448
- 271 Benin City1,845,432
- 305 Warri1,607,702
How to read this: the figure in front of a name is where that city stands among the 12,138 cities the UN counted in 2025, and each bar is its people, on one scale per list. Numbers are missing where a city has fewer than 300,000 people and so has no page of its own.
Apparatus
Sources and method
The figures for Onitsha are the UN's own, at five-year steps: an estimate for each of 1975 to 2025, then projection to 2050. Projected years are drawn hatched, and the UN publishes no range of uncertainty for a city. What a city means here, how the UN measures one, and why that number can differ from the one Onitsha publishes about itself: how the figures here are put together.
Sources: UN WUP 2025 · Natural Earth · flag-icons. Every source, its licence and how to cite it →
Verified 2026-09-30 · 73 canaries