Deposit mobilization is the most important service and an integral part of banking operations. In Ethiopia, mobilizing savings through intense deposit collection has been regarded as the major task of banking. However, managing deposits is impossible without understanding and controlling the factors that influence them. Thus, this study examined the bank-specific and macroeconomic determinants of deposit mobilization in Ethiopian banking sectors using balanced panel data of 14 commercial banks from 2011 to 2020. Secondary data sources from sampled commercial bank audited financial statements were used to achieve the stated objective. A quantitative approach and explanatory design were employed. The model result demonstrated that loan to deposit ratio, capital adequacy, economic growth, inflation, population growth, and political stability have a negative and statistically significant effect on commercial bank deposit mobilization. On the other hand, the bank's profitability has a positive and statistically significant impact on commercial bank deposit growth. The study suggests that Ethiopian commercial banks need to improve deposit mobilization by paying more attention to internal factors controlled by management, while keeping in mind the influence of the overall economic and political dynamic. This study provides useful insights for bank managers, owners, analysts, policymakers, depositors, and other stakeholders on the deposit growth of commercial banks and its determinants. Meanwhile, academic researchers and students may use the findings and suggestions to conduct a study in the banking area. Unlike the previous studies, the present study examined the effect of population growth and political stability on deposit mobilization and contributes to the limited stock of existing knowledge in the area.