The relevance of this study is determined by the need to adapt Ukraine’s grain sector to wartime challenges, the transformation of global trade, and the search for new directions for the diversification of grain crop exports. The aim of the study was to assess the transformation of the geographical structure of Ukraine’s grain exports, determine the level of concentration in the global wheat, maize, and barley markets, and substantiate directions for enhancing the resilience of the grain sector under conditions of wartime instability. The study employed statistical, comparative, and systems analysis methods, as well as the Herfindahl-Hirschman Index and the concentration ratio. It was established that the global maize market was characterised by a high level of concentration, whereas the wheat and barley markets exhibited moderate concentration. The findings demonstrated that Ukraine has maintained its position as one of the leading exporters of grain crops even under the conditions of Russia’s full-scale war against Ukraine. During 2022-2024, a significant transformation occurred in the geographical structure of exports: the role of the European Union, African, and Asian countries increased, while dependence on individual traditional markets gradually declined. It was established that the diversification process was phased in nature: in 2022, forced adaptation to logistical constraints predominated; in 2023, active reorientation of export flows took place; and in 2024, the new multi-regional export model became stabilised. This reduced the risks associated with excessive dependence on individual export destinations and increased the flexibility of foreign trade activities. In certain segments, particularly barley exports, a high concentration of supplies to China was observed, with its share reaching 48.7% in 2025. It was determined that the key factors enabling the adaptation of the grain sector included the development of alternative logistics routes through Danube ports and EU land corridors, as well as expanded presence in new export markets. It was substantiated that the development of deep grain processing and the production of higher value-added products became an important factor in reducing the vulnerability of the agricultural sector to external economic and logistical shocks. The practical value of the study lies in substantiating directions for export diversification, the development of grain processing, and the modernisation of logistics infrastructure in order to enhance the competitiveness and resilience of Ukraine’s agricultural sector