Profitability is an important indicator for assessing the ability of Islamic banks to maintain operational sustainability and effectively perform their financial intermediation function. This study aims to examine the effects of Third-Party Funds (TPF) and Non-Performing Financing (NPF) on Return on Assets (ROA) of Islamic banks listed on the Indonesia Stock Exchange during the 2020–2024 period. The study employs a quantitative approach with a causal-associative research design. Secondary data are collected from annual financial reports of Islamic banks, the Indonesia Stock Exchange, and the Financial Services Authority. Samples are selected using purposive sampling based on several criteria, including Islamic banks listed on the Indonesia Stock Exchange, consistent publication of financial statements, and complete availability of TPF, NPF, and ROA data during the observation period. Data are analyzed using descriptive statistics, classical assumption tests, multiple linear regression, partial tests, simultaneous tests, and the coefficient of determination. Conceptually, higher third-party funds enable Islamic banks to expand productive asset allocation, potentially improving profitability. In contrast, higher NPF reflects deteriorating financing quality, which may increase impairment costs and reduce bank profitability. This study is expected to provide empirical evidence regarding the roles of fund-raising capacity and financing quality in determining the profitability of Indonesian Islamic banks, particularly during the COVID-19 pandemic and post-pandemic economic recovery period.