This study aimed to explain the homeland and the migration process of the Sumbawa ethnic, Indonesia. Data were collected using documentation, interview, and observation methods, and data analysis used a top-down approach and a language comparison method (Proto-Austronesian and Prelanguage Sumbawa etymon to Sumbawanes dialects). Linguistic heterogeneity pointed to the area west of Sumbawa as the homeland. The area’s phonological characteristics are notable for retaining the Sumbawa Prelanguage and Proto-Austronesian: *i and *u. This area also preserves linguistic forms that convey the meanings ‘down’, ‘knee’, ‘blunt’, and ‘thin’. Migration from the homeland occurs in five phases, namely (1) a southward migration towards the Tongo area, (2) a northward migration towards the Taliwang and Sumbawa Besar areas, (3) a movement from the Tongo dialect center to its subdialect areas, (4) a movement from the homeland to the Jereweh dialect area, and each from the Sumbawa Besar dialect center and the Taliwang dialect to their subdialect areas, and (5) a movement from the Jereweh dialect center to its subdialect area. Overall, this study concluded that the Jereweh dialect area in western Sumbawa is the homeland of the Sumbawa ethnic group, with migration occurring in five stages.