The theoretical foundations of the ecosystem approach to the digitalization of the Russian agro-industrial complex are considered. The hypothesis of this study was the assumption that the digital ecosystem is a higher level of cooperation in the agro-industrial complex, involving the unification of all participants on a digital platform and with the help of digital technologies. Digital ecosystems meet all the requirements of the sixth technological order and allow agricultural producers to move to it at a faster pace. It is shown that digital ecosystems accelerate the process of introducing digital technologies into the agro-industrial complex (its digitalization), thereby contributing to the effective functioning of ecosystems, i.e. these are interrelated categories. It is proposed to understand the digitalization of the agro-industrial complex as “the mass introduction of digital technologies, the increase in the use of digital and/or computer technologies in the economic activities of an individual agro-industrial complex enterprise, a household or the agricultural sector of the economy as a whole." and the “digital ecosystem of the regional agro-industrial complex” is a set of organizational and economic tools, promoting the construction of mutually beneficial production relations between subjects of the region’s agro-industrial complex using a digital platform to increase the share of small and medium-sized agricultural producers in the regional market for agricultural products, and ultimately, to ensure the sustainability of the rural economy through the creation of new cooperative ties.