The contemporary world is characterized by accelerating innovations in a dense knowledge pool which is a byproduct of networked relationships in a complex ecosystem. In this manner, open innovation has become a revolutionary paradigm in the quickly changing innovation landscape by encouraging cooperation, cross-disciplinary information exchange, and idea co-creation. When used in complex ecosystems, this strategy enhances the intangible capital by amplifying the collective intelligence of many players. Today it is evident that open environments for knowledge, provide higher rates of innovation and hence more productivity and comparative advantage. Following the critical importance of the concept, this study tries to highlight the mutual beneficial interaction between open innovation principles in knowledge networks and complex ecosystems, by using a comprehensive and systematic literature review. In this context, this study underlines the increasing importance and attention of open innovation practices within intricate ecosystems. It emphasizes the need to manage intellectual property, facilitate cooperation and continue skill development as crucial policy elements to build an environment favorable to effective open innovation across complex ecosystems. In the light of the related literature, it seeks to offer insights for organizations by exploring the relationship between OI and complex ecosystems. Hence, the study contributes to the related literature by underlying the interplay between open innovation in complex ecosystems and the role of knowledge networks.