Seagrass ecosystems, which are marine flowering plants, provide essential ecosystem services such as biodiversity enhancement, coastal protection, and carbon sequestration. Despite their importance, these ecosystems have been declining across Europe, with a net loss of approximately 35,000 hectares between 1869 and 2016. The decline is attributed to multiple factors, including poor water quality, coastal modification, mechanical damage, overfishing, land-sea interactions, and climate change. To address this, a group of experts from across Europe used the Delphi method to identify 100 priority questions that, if answered, could significantly advance seagrass conservation and restoration efforts. These questions cover nine themes: Biodiversity & Ecology, Ecosystem Services, Blue Carbon, Fisheries Support, Drivers & Threats, Monitoring & Assessment, Conservation & Restoration, Governance, Policy & Management, and Communication. The aim is to fill knowledge gaps, improve monitoring and research, and enhance policy and management to ensure the recovery and resilience of European seagrass ecosystems. The paper emphasizes the need for interdisciplinary collaboration, improved communication, and effective governance to achieve these goals.Seagrass ecosystems, which are marine flowering plants, provide essential ecosystem services such as biodiversity enhancement, coastal protection, and carbon sequestration. Despite their importance, these ecosystems have been declining across Europe, with a net loss of approximately 35,000 hectares between 1869 and 2016. The decline is attributed to multiple factors, including poor water quality, coastal modification, mechanical damage, overfishing, land-sea interactions, and climate change. To address this, a group of experts from across Europe used the Delphi method to identify 100 priority questions that, if answered, could significantly advance seagrass conservation and restoration efforts. These questions cover nine themes: Biodiversity & Ecology, Ecosystem Services, Blue Carbon, Fisheries Support, Drivers & Threats, Monitoring & Assessment, Conservation & Restoration, Governance, Policy & Management, and Communication. The aim is to fill knowledge gaps, improve monitoring and research, and enhance policy and management to ensure the recovery and resilience of European seagrass ecosystems. The paper emphasizes the need for interdisciplinary collaboration, improved communication, and effective governance to achieve these goals.