The Rwa or Meru sometimes Rwo are a Bantu ethnic and linguistic group based on the south and eastern slopes of Mount Meru in Meru District of the Arusha Region of Tanzania, the Rwa population is estimated to number 198,000.

Meru District, officially the Meru District Council is one of seven districts of the Arusha Region of Tanzania.The District is bordered to the north by Longido District, to the east by Siha and Hai Districts of Kilimanjaro Region, to the south by Simanjiro District of Manyara Region, and to the west by Arusha Rural District and Arusha Urban District. It covers an area of 1,266 km2 (489 sq mi). The district is comparable in size to the land area of Faroe Islands. Meru District has an max elevation of 3,800 m (12,500 ft) at Rhino Point on Mount Meru. The administrative capital of the district is Usa River. According to the 2022 Tanzania National Census, the population of Meru District council was 331,603.