This paper provides a comparative analysis of the association between student achievement and public-private partnerships (PPPs) in education across different countries. It uses student-level data from the PISA international student achievement test that provides information on the public-private character of both operation and funding of each tested school. The cross-country “big picture” results suggest that public school operation is associated with lower student outcomes, but public school funding with better student outcomes. Thus, systems of PPPs that combine private operation with public funding do best among all possible operation-funding combinations, while systems of PPPs that combine public operation with private funding do worst. Within-country results suggest that the advantage of private operation is particularly strong in countries with large shares of public funding. The results favor educational PPPs of the form where the state does the funding and the private sector runs the schools.