The author examines the ecosystem approach, corporate innovation ecosystems and intercorporate innovation ecosystems. Considering the importance of their development for achieving the required pace of innovative development of Russian companies and the Russian economy, the study of their condition and development prospects determines the purpose of this paper. An analysis of the literature revealed an increase in the number of studies on innovation ecosystems and their diversity, indicating the potential for further development of the concept of innovation ecosystems. The analysis of the innovative activity of Russian companies shows that the main indicators reflecting the degree of innovative development in Russia in 2019–2022 are growing, but not enough. The average share of innovation costs in 2020–2022 was 2.1%, and in industry – only 1.7%, there was a reduction in the volume of inter-enterprise cooperation on the development of innovations. The author formulated the definition of a corporate innovation ecosystem as a singular innovation ecosystem established by a given company to create innovative value necessary for its development. The author has also formulated the features of its configuration that determine the logic of its functioning. The results of the study show the high potential for scientific and technological cooperation between Russian companies. Therefore, the author formulated the concept of an Intercorporate Innovation Ecosystem, which is a singular innovation ecosystem created on the initiative of two or more participants by partially integrating their corporate innovation ecosystems into an Intercorporate Innovation Ecosystem. Their aim is to carry out joint innovation activities and then independently commercialise the results. The proposed concept, implemented in accordance with the principles of the ecosystem approach, in terms of contractual relations, as well as implying the development of a single platform or functioning on a multi-platform basis, has theoretical validity and seems applicable in the practice of Russian companies and significant for the development of the Russian economy.