Objective: To evaluate the cascade of HIV care in Oman in 2018 and the longitudinal change in each step from 2015 to 2018. Methods: Population-based data on all diagnosed people living with HIV reported to the National AIDS Programme in 1984–2018 were used. Results: As of December 31, 2018, the estimated number of people living with HIV in Oman was 3030; 1532 (50.6%) were aware of their infection. Of the diagnosed patients, 95.9% were linked to care, 85.8% were retained in care, and 84.3% were on ART. The proportions of patients with viral suppression out of all people with HIV, the diagnosed persons, and those on ART were 37.3%, 73.7%, and 87.5%, respectively. The proportion of patients linked to care increased from 72.6% in 2015 to 95.6% in 2018 (p 0.001). Only 57% (947/1661) were retained in care in 2015, which increased to 76.9% (1193/1552) in 2017 and 85.8% (1314/1532) in 2018 (p 0.001). Viral suppression increased from 75.7% (672/888) in 2015 to 84.5% (859/1017) in 2016 and 87.5% (1129/1291) in 2018 (p 0.001). Conclusions: A sustained improvement in linkage to care, retention in care, ART coverage, and viral suppression was observed amongst people living with HIV in Oman in 2015–2018.