Financial planning constituted a fundamental management function that determined organizational sustainability and profitability in the non-profit sector. This study examined the effect of financial planning on profitability at International Alert Uganda, investigating how budgeting, cash flow management, financial forecasting, and investment decisions influenced the organization's financial performance and operational sustainability. The study employed a descriptive case study design utilizing both quantitative and qualitative approaches. A sample of 76 respondents was selected from a population of 95 staff members using purposive and stratified random sampling techniques. Data were collected through structured questionnaires and interviews with senior management. Statistical Package for Social Sciences (SPSS) version 26 was used to analyze data through descriptive statistics, Pearson correlation analysis, and multiple regression analysis to establish relationships between financial planning components and organizational profitability. The findings revealed a significant positive relationship (r=0.813, p