This study examined the contribution of budgeting practices, timeliness, variance analysis, and transparency to the financial performance of private secondary schools in Kagadi District, Western Uganda. Using a cross-sectional survey design with mixed methods, data were collected from 255 respondents across 22 private secondary schools through questionnaires, key informant interviews, and documentary review. Descriptive statistics, Pearson correlation, and multiple regression analyses were employed. Results reveal that budgeting practices in terms of timeliness (r = .357), variance analysis (r = .423), transparency (r = .488), and financial performance (p < .01) are positively and significantly associated with financial performance. Multiple regression analysis revealed that budgeting practices explain 25.3% of the variation in financial performance (R² = .253). Transparency emerged as the only statistically significant and strongest predictor of financial performance (β = .368, p < .001), while timeliness and variance analysis showed positive but statistically insignificant effects when modeled jointly. Qualitative evidence indicates weak institutionalization of variance analysis and limited stakeholder participation, which constrains the effectiveness of budgeting as a financial management tool. The study underscores the need for transparent, participatory, and analytically driven budgeting systems to enhance financial sustainability in private secondary schools.