| Kati | |
| Nickname: | National Park district |
| Settlement Type: | District of South Zanzibar |
| Coordinates: | -6.0997°N 39.2997°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Region |
| Subdivision Name1: | Unguja South Region |
| Seat Type: | Capital |
| Seat: | Tunguu |
| Area Total Km2: | 505.8 |
| Area Rank: | 1st in Unguja South |
| Population Demonym: | Zanzibari Kati |
| Population As Of: | 2022 |
| Population Total: | 132,717 |
| Population Density Km2: | auto |
| Population Rank: | 1st in Unguja South |
| Demographics Type1: | Ethnic groups |
| Demographics1 Title1: | Settler |
| Demographics1 Info1: | Swahili |
| Demographics1 Title2: | Native |
| Demographics1 Info2: | Hadimu |
Kati District (Wilaya ya Kati in Swahili) is one of two administrative districts of Unguja South Region in Tanzania.[1] The district covers an area of .[2] The district is comparable in size to the land area of Guam.[3] The district has a water border to the east and west by the Indian Ocean. The district is bordered to the north by Kaskazini B District of Unguja North Region. To the south Kati District is bordered by Kusini District. The district seat (capital) is the town of Tunguu. The district is the birthplace of Bi Kidude, most famous Zanzibari musician born in Kitumba Village. According to the 2022 census, the district has a total population of 132,717.[4] The Zanzibar University is located in Tunguu and was founded in 2002.
As of 2012, Kati District was administratively divided into 11 wards.[5]