| Hai Mjini Ward | |
| Official Name: | Kata ya Hai Mjini, Wilaya ya Hai |
| Settlement Type: | Ward |
| Pushpin Map: | Tanzania |
| Subdivision Type: | Country |
| Subdivision Type1: | Region |
| Subdivision Name1: | Kilimanjaro Region |
| Subdivision Type2: | District |
| Subdivision Name2: | Hai District |
| Area Total Km2: | 54 |
| Population As Of: | 2012 |
| Population Total: | 34,098 |
| Population Density Km2: | auto |
| Elevation M: | 1,388 |
Hai Mjini is an administrative ward in Hai District of Kilimanjaro Region in Tanzania. The ward covers an area of,[1] and has an average elevation of .[2] According to the 2012 census, the ward has a total population of 34,098.[3]
The ward contains the rapidly growing town of Boma Ng'ombe (alternately spelled as "Bomang'ombe") meaning a bovine palisade. The population of Boma Ng'ombe,[4] based on the 2002 Tanzanian census,[5] was 17,674. Geographically, Boma Ng'ombe is located between the Sanya River and the Mungushi gulch and straddles the Arusha-Himo road about 17 kilometers from the Kilimanjaro International Airport. The headquarters of the Hai District is just to the north of that road. The town has a public market open twice per week.[6] There are numerous schools in Boma Ng'ombe; however, the only A-Level school within the ward as of 2012 was Isala High School.[7]