The 1994 national census reported a total population for this woreda of 68,919, of whom 33,587 were men and 35,332 women; 7,675 or 11.14% of its population were urban dwellers at the time. The two largest ethnic groups reported in Sibu Sire were the Oromo (86.06%), and the Amhara (12.24%); all other ethnic groups made up 1.7% of the population. Oromiffa was spoken as a first language by 86.73%, and 12.22% spoke Amharic; the remaining 1.05% spoke all other primary languages reported. The majority of the inhabitants were Ethiopian Orthodox Christianity, with 72.43% of the population reporting they observed this belief, while 17.32% of the population said they were Protestant, and 9.31% were Moslem.