A cross-sectional study was conducted from June 2018 to November 2018 to determine the prevalence of ovine fasciolosis in Oromia region, South West Shoa, 285 fecal samples were randomly collected directly from the rectum of individual animals. Parasitological investigation was performed using sedimentation technique. From 285 coprologically examined sheep, 150 animals found positive for fasciolosis with an overall prevalence of 52.63%. Difference in prevalence rate observed among the three study sites from which the samples were collected. Hence, the prevalence rates recorded were 46.6% in Qarsa Galute 23.3% in Qarsabonbi and 30% BurqaGode. The difference in the prevalence in the three study sites was not statistically significant (p>0.05). The prevalence of ovine fasciolosis was computed for the different age, sex and season categories. The prevalence rate of fasciolosis in young sheep 20% was less than in adults sheep 80% and the difference were not statistically significant (P>0.05). The prevalence of fasciolosis in two sex groups in the present study was 66.66%, 33.33%in female and male respectively. The difference in the prevalence was not significant (p>0.05). Seasonal prevalence of ovine fasciolosis the highest prevalence was recorded 33.3%, 20%, 16%, 14.6%, 9.3%, and 6.66%, during the months of in June, November, July, October, September and August respectively. The difference in monthly prevalence was significant (P< 0.05).