Mombasa is the second-largest city in Kenya. Lying next to the Indian Ocean, it has a major port and an international airport. The city also serves as the centre of the coastal tourism industry.

Also known as Mombas in colonial times, its name derives from Manbasa. This was the Arabic name of the former sultanate of Mvita, which had its capital here. In modern times the town is the headquarters of Mombasa District, which, like most other districts in Kenya, is named after its chief town.

The city has a population of 939,370, as per the 2009 census,^{[citation needed]} and is located on Mombasa Island, which is separated from the mainland by two creeks: Tudor Creek and Kilindini Harbour. The island is connected to the mainland to the north by the Nyali Bridge, to the south by the Likoni Ferry and to the west by the Makupa Causeway, alongside which runs the Kenya-Uganda Railway. The port serves both Kenya and countries of the interior, linking them to the Ocean. The city is served by Moi International Airport located in the northwest mainland suburb of Chaani, northwest of Changamwe area.

Mombasa District is one of the 71 districts of Kenya. Its capital and the only town is Mombasa.

Kenya is divided into eight provinces, which are subdivided into 71 districts. In Coast Province there are seven districts, Mombasa District being one of them. It is situated in the southeast of Coast Province. It is the smallest in size covering an area of 294.6 km² including 65 km² of inshore waters. The district lies between latitudes 3°56’ and 4°10’ south of the equator and longitudes 39°34’ and 39°46’ east.

The district and the town are divided into four divisions namely:

The district has four constituencies:

Mombasa District lies within the coast lowland, which rises gradually from the sea level in the east to slightly over 76 m above sea level in the mainland west. The highest point is at Nguu Tatu hills in the mainland North that rises up to 100 m above sea level.