Mirab Hararghe (or "West Hararge") is one of the Zones in the Ethiopian Region of Oromia. West Hararghe takes its name from the former province of Hararghe. West Harerge is bordered on the south by the Shebelle River which separates it from Bale, on the southwest by Arsi, on the northwest by the Afar Region, on the north by the Somali Region and on the east by East Hararghe. Towns in West Hararghe include Chiro, Bedessa, Gelemso, and Mieso.
The highest point in this Zone is Mount Arba Gugu (3574 meters).
The Central Statistical Agency (CSA) reported that 8,364.00 tons of coffee were produced in West Hararghe in the year ending in 2005, based on inspection records from the Ethiopian Coffee and Tea authority. This represents 7.27% of the Region's output and 3.7% of Ethiopia's total output.
Based on the 2007 Census conducted by the CSA, this Zone has a total population of 1,871,706, an increase of 47.16% over the 1994 census, of whom 958,861 are men and 912,845 women; with an area of 15,065.86 square kilometers, West Hararghe has a population density of 124.23. While 160,895 or 9.36% are urban inhabitants, a further 10,567 or 0.56% are pastoralists. A total of 395,127 households were counted in this Zone, which results in an average of 4.74 persons to a household, and 380,019 housing units. The three largest ethnic groups reported were the Oromo (90.12%), the Amhara (7.24%) and the Somali (1.26%); all other ethnic groups made up 1.38% of the population. Oromiffa was spoken as a first language by 89.47%, Amharic was spoken by 8.82% and Somali by 1.2%; the remaining 0.51% spoke all other primary languages reported. The majority of the inhabitants were Muslim, with 88.05% of the population having reported they practiced that belief, while 11.11% of the population professed Ethiopian Orthodox Christianity.