Background: Oral rehydration salt therapy is a critical intervention to reduce mortality and morbidity of children with diarrheal diseases. However, it remains underused in low- and middle-income countries. In Ethiopia, only less than half of children with diarrheal diseases were treated with oral rehydration salt solution. Therefore, the objective of this study was to identify the determinants of oral rehydration salt utilization among children with diarrhea in Ethiopia. Method: A secondary data analysis was done using the 2016 Ethiopian Demographic and Health Survey. A weighted sample of 1227 children who had diarrhea in the last 2 weeks with their index mothers during the 5 years survey was included in the study. A multilevel mixed logistic regression model was fitted to identify factors associated with oral rehydration salt utilization. Finally, statistical significance was declared at p-value < 0.05. Result: The overall prevalence of oral rehydration salt utilization for children with diarrhea was 29.5%. In this study, age of mother ⩾35 (adjusted odds ratio = 1.66, 95% confidence interval = 1.05, 2.64), mothers with formal education (adjusted odds ratio = 1.52, 95% confidence interval = 1.09, 2.11), media exposure (adjusted odds ratio = 1.72, 95% confidence interval = 1.25, 2.38), living in Metropolitan regions (Addis Ababa and Dire Dawa (adjusted odds ratio = 1.76, 95% confidence interval = 1.14, 2.69)), and small peripheral regions (Afar, Gambela, Somalia, Benishangul-Gumuz (adjusted odds ratio = 1.69, 95% confidence interval = 1.22, 2.34)) were associated with higher odd of oral rehydration salt utilization for children with diarrhea. Conclusion: The study concludes that the age of mothers, educational status of the mother, media exposure, and regions of mothers were determinants of oral rehydration salt utilization for children with diarrhea. Therefore, media advertising regarding diarrhea management should be scaled up to increase oral rehydration salt utilization for children with diarrhea. Special attention to socio-cultural constraints or beliefs regarding diarrhea management should be given to mothers from large to center (Tigray, Amhara, Oromia, Southern Nations Nationalities, and People’s Region, and Harari) regions.