Savings and Credit Cooperative Organizations (SACCOs) in Wakiso District, Uganda home to over 50 registered SACCOs serving more than 200,000 members played a vital role in financial inclusion, SME growth, and agriculture. However, they faced persistent financial challenges, including declining Return on Assets (ROA), NonPerforming Loan (NPL) ratios exceeding 12% (above UMRA's 5% benchmark), and internal control weaknesses like poor segregation of duties and fraud risks (Auditor General Reports, 2022–2024; UMRA, 2025). This study examined the perceived influence of COSO (2013) internal control components control environment, risk assessment, control activities, information & communication, and monitoring on SACCO financial performance (ROA, ROE, NPL ratios, liquidity, solvency), grounded in Agency Theory (Jensen & Meckling, 1976) and Contingency Theory (Donaldson, 2001). Employing a mixed-methods explanatory sequential design, it analyzed survey data from 105 experienced respondents (mean tenure: 7.2 years) across 20 purposively selected SACCOs, secondary financial data (2020–2025), and semi-structured interviews with 15–20 key informants.Findings revealed moderately to highly positive perceptions of controls, with strengths in control activities (e.g., 83.8% endorsement of approvals) and monitoring (80.0% for corrections), driving gains like 83.9% perceived NPL reductions and 95.2% liquidity improvements. Communication emerged as a key weakness (59.0% dissatisfaction). Conclusions affirmed controls' role in resilience, with recommendations for ethics training, digital tools, and regulatory mandates. The study suggested future research via regressions and regional comparisons.