Nairobi is the capital city of Kenya and the largest city in the country. It's situated in the south-central part of Kenya. Nairobi is among the most influential cities in Africa and one of the most diverse. It is the country’s economic, transportation, and cultural centre. Since its foundation, Nairobi is renowned for influencing other cities around Africa. It is famous for its remarkable wildlife, Nairobi National Park, Nairobi Railway Museum, Nairobi National Museum, and the Maasai Market.

Census in Kenya is done after every 10 years and 2019 was the last time that it was conducted. The next census is scheduled for 2029 in Kenya. According to the 2019 census, Nairobi had a population of 4,397,073. Compared to other cities in Kenya, Nairobi is considered to be more diverse. According to the 2019 census, 70% of the population is Christian based in Nairobi while the rest of the population is of different religions. As one of the most diverse cities in Africa, Nairobi houses over 4 million residents, who collectively speak over 60 languages, including Swahili, English, and numerous local dialects. Nairobi National Park, the city's most famous landmark, is the only game reserve located within a city in the world.

There are two tiers under local government in Nairobi. They are the county and sub-county tiers. Countywide administration is coordinated by the Nairobi City County Government, while local administration is carried out by sub-county administrations. The Nairobi City County Government consists of the Governor and the Nairobi City County Assembly. The Governor has executive powers, and the Nairobi City County Assembly scrutinizes the Governor's decisions and can accept or reject his budget proposals each year. The Nairobi City County Government is responsible for strategic planning, policing, the fire service, most aspects of transport and economic development. On the other hand, the sub-county administrations are responsible for local services not overseen by the County government, such as local planning, schools, social services, local roads and refuse collection.

Nairobi has always been a commercial city and today enjoys the status of having one of the largest city economies in Africa. The city thrives in trade and commerce and has a vibrant culture seeped in commerce. It has a GDP of over $28 billion, which is about 20 percent of Kenya's total GDP. The size of its economy is larger than that of several African nations. Nairobi is home to thousands of Kenyan businesses and over 100 major international companies and organizations.

Nairobi is home to East Africa’s largest infrastructure projects. The Nairobi Metropolitan Services Improvement Project (NaMSIP) aims to improve the institutional and physical infrastructure in Nairobi and its satellite towns. It identifies a range of infrastructure priorities for Nairobi, from new energy, water and sewerage infrastructure, to enhanced digital connectivity and new rail and road schemes. Some of the investment is provided by the private sector, through privatized utilities. This has generally worked well in Nairobi, although business is particularly concerned at the lack of capacity in digital infrastructure. The take-up of high speed broadband by business is low compared to other world cities; and just over 10% of premises cannot access superfast broadband in the first place, with these “not spots” particularly prevalent in the City of Nairobi and its surrounding areas.