Nairobi is the capital and largest city of Kenya. The name is derived from the Maasai phrase Enkare Nairobi, which translates to 'place of cool waters', a reference to the Nairobi River which flows through the city. The city proper had a population of 4,397,073 in the 2019 census. The Greater Nairobi Metropolitan Area has a population of about 7,000,000 people. The city is commonly referred to as The Green City in the Sun.

Kenya, officially the Republic of Kenya, is a country in East Africa. With a population of more than 47.6 million in the 2019 census, Kenya is the 28th most populous country in the world and 7th most populous in Africa. Kenya's capital and largest city is Nairobi, while its oldest and second largest city, is the major port city of Mombasa, situated on Mombasa Island in the Indian Ocean and the surrounding mainland. Mombasa was the capital of the British East Africa Protectorate, which included most of what is now Kenya and southwestern Somalia, from 1889 to 1907. Other important cities include Kisumu and Nakuru. Kenya is bordered by South Sudan to the northwest, Ethiopia to the north, Somalia to the east, Uganda to the west, Tanzania to the south, and the Indian Ocean to the southeast. Kenya's geography, climate and population vary widely, ranging from cold snow-capped mountaintops with vast surrounding forests, wildlife and fertile agricultural regions to temperate climates in western and rift valley counties and further on to dry less fertile arid and semi-arid areas and absolute deserts.