Nairobi City County is one of the 47 counties of Kenya. With an estimated population of 5,454,000 in 2024, it is the third smallest yet the most populous of the counties, also serving as the capital of Kenya. In 2013, the county entity was effected, replacing Nairobi City Council, the long-standing unit of administration since pre-independence. The city county consists of eleven gazetted sub-counties and eighty five electoral wards. On the national level, Nairobi also sends seventeen Members of Parliament across the constituencies and one County Woman Representative to the National Assembly; one senator to the Senate. The county government, which is allocated devolved functions as per the constitution, is headed by the county governor, who appoints his cabinet. The county's legislature is headed by the County Speaker, who presides over the County Assembly: single-member elected Members of the County Assembly (MCAs) represent their respective electoral wards. Additional MCAs are also nominated by political parties as a form of affirmative action.

The Senate of the Republic of Kenya is one of the two Houses of the Parliament of Kenya, along with the National Assembly. The Senate was first established as part of Kenya's 1963 Constitution.