The 2007 national census reported this woreda's total population as 108,406, of whom 54,186 were men and 54,220 women; 865 or 0.8% of its population were urban dwellers. The majority of the inhabitants (51.82%) said they practised Ethiopian Orthodox Christianity, while 32% of the population practiced traditional religions, and 15.9% were Protestant.[4]
Based on figures published by the Central Statistical Agency in 2005, this woreda has an estimated total population of 260,193, of whom 131,922 are men and 128,271 women; 70,675 or 27.16% of its population are urban dwellers, which is greater than the Zone average of 12.3%. With an estimated area of 1,588.13 square kilometers, Ambo has an estimated population density of 163.8 people per square kilometer, which is greater than the Zone average of 152.8.[5]
The 1994 national census reported a total population for this woreda of 177,465, of whom 87,325 were men and 90,140 women; 39,535 or 22.28% of its population were urban dwellers at the time. The two largest ethnic groups reported in Ambo were the Oromo (92.58%), and the Amhara (5.76%); all other ethnic groups made up 1.16% of the population. Oromiffa was spoken as a first language by 90.92%, and 8.37% spoke Amharic; the remaining 0.81% spoke all other primary languages reported. The majority of the inhabitants professed Ethiopian Orthodox Christianity, with 74.16% of the population reporting they practiced that belief, while 18.77% of the population said they held traditional beliefs, and 6.07% were Protestant.[6]