Public–private partnerships (PPP) have evolved as a choice of infrastructure procurement for numerous developing countries, particularly in the water and power sectors, thereby capturing the interest of researchers. A rich body of literature exists in the field of PPPs, as well as their critical success factors (CSF). Despite the valuable insights garnered from individual studies, a research gap exists in conducting a meta-synthesis of the findings from multiple developing countries and investigating the broader elements and themes of power and water PPP CSF research. This systematic review employed the PRISMA protocol and identified 30 records. We explored the regions, sectors, yearly output, adopted research methods, key authors, and themes of the corpus reviewed. The review recognised four emerging trends in the records, which are identifying, ranking, exploring the interrelationship, or utilising CSFs. The review identified the top 30 frequent CSFs in the corpus, as well as their ranking by importance across multiple settings. The review concludes by addressing geographic and methodological limitations and proposing directions for future research.