Liquidity is essential for the effective functioning and financial sustainability of public secondary schools because it enables institutions to meet short-term financial obligations and maintain uninterrupted service delivery. Despite the implementation of the Free Day Secondary Education (FDSE) programme in Kenya, many public secondary schools continue to experience liquidity challenges arising from delayed government capitation, increasing operational costs and inadequate working capital financing. These challenges constrain schools' ability to finance recurrent expenditures, settle short-term liabilities and sustain educational activities. This study examined the effect of working capital financing strategies on the liquidity of public secondary schools in Matungulu Sub-County, Kenya. A descriptive correlational research design was adopted and a census approach was used to include all the 38 public secondary schools in the sub-county. Primary data were collected using structured questionnaires administered to principals, bursars and accounts clerks, while secondary data were obtained from audited financial statements. Descriptive statistics and multiple linear regression analysis were employed to analyse the data after confirming that the assumptions of regression analysis had been satisfied. The findings revealed that the mean current ratio was 0.898, indicating that most schools operated below the recommended working capital threshold. Further, regression analysis established that working capital financing strategies had a positive but statistically insignificant effect on liquidity (β = 0.463, p = 0.352). The findings imply that although appropriate working capital financing contributes positively to liquidity, its effectiveness is constrained by external funding delays and institutional financial limitations. The study concludes that strengthening working capital financing practices alone may not significantly improve liquidity unless complemented by timely government capitation, effective financial planning and sound internal financial management systems. The study recommends that school management, Boards of Management and the Ministry of Education strengthen working capital financing policies, improve cash flow planning, enhance internal financial controls and ensure timely disbursement of government capitation to promote financial sustainability in public secondary schools.