Coopetition (also spelled co-opetition, coopertition or co-opertition) is a concept in which firms or individuals engage in both cooperation and competition simultaneously. It describes situations where competing entities work together toward a common goal or share resources while still maintaining competitive interests in other areas. The term is a portmanteau of "cooperation" and "competition".

In business strategy, coopetition can involve companies collaborating in areas like research and development, standard-setting, or supply chain management—while competing in product offerings or market share. For example, two technology firms might jointly develop a new platform standard while continuing to compete in the end-user market. Coopetition can occur at both the inter-organizational level, where companies partner with competitors, and the intra-organizational level, where departments or teams within the same organization both collaborate and compete for resources or influence.

The concept is rooted in game theory, particularly in models that go beyond purely competitive (non-cooperative) or purely collaborative games. Foundational ideas were introduced in the 1944 book Theory of Games and Economic Behavior by John von Neumann and Oskar Morgenstern, and further developed in the work of John Forbes Nash.

The concept and term coopetition and its variants have been re-coined several times in history.

The concept appeared as early as 1913, being used to describe the relationships among proximate independent dealers of the Sealshipt Oyster System, who were instructed to cooperate for the benefit of the system while competing with each other for customers in the same city.

The term and the ideas around co-opetition gained wide attention within the business community after the publication in 1996 of the book by Brandenberger and Nalebuff bearing the same title. Until today this remains the reference work for both researchers and practitioners alike.

Giovanni Battista Dagnino and Giovanna Padula's conceptualized in their conference paper (2002) that, at the inter-organisational level, coopetition occurs when companies interact with partial congruence of interests. They cooperate with each other to reach a higher value creation, if compared to the value created without interaction, and struggle to achieve a competitive advantage.

Often coopetition takes place when companies that are in the same market work together in the exploration of knowledge and research of new products, at the same time that they compete for the market-share of their products and in the exploitation of the knowledge created. In this case, the interactions occur simultaneously and in different levels in the value chain. This is the case in the arrangement between PSA Peugeot Citroën and Toyota to share components for a new city car—simultaneously sold as the Peugeot 107, the Toyota Aygo, and the Citroën C1, where companies save money on shared costs while remaining fiercely competitive in other areas.