The Marine Strategy Part Three: 2025 UK Programme of Measures outlines the measures the United Kingdom will implement to achieve or maintain Good Environmental Status (GES) for its marine environment. The document serves as an update to the previous strategies, adhering to the requirements of the Marine Strategy Regulations 2010. The programme adopts an ecosystem-based management approach, aiming to protect, prevent deterioration, and restore the marine environment while allowing sustainable use of resources. It emphasizes international collaboration, particularly with neighboring countries in the Greater North Sea and Celtic Seas, to address regional pressures. The strategy identifies 11 descriptors essential for GES, ranging from biodiversity and non-indigenous species to contaminants and underwater noise. Each descriptor includes assessments of current status, measures required to progress toward GES, and exceptions where achieving GES is hindered by external factors like climate change. Existing measures, primarily from the 2015 programme, remain relevant and are supplemented by new initiatives tailored to evolving pressures and knowledge gaps. The strategy also acknowledges the socio-economic impacts of proposed measures, ensuring they are sustainable for current and future generations. It includes specific actions coordinated across the UK and devolved governments, with some measures implemented individually due to the nature of devolution. The programme highlights the importance of regular reviews to adapt to changing environmental pressures, emphasizing the role of research and stakeholder engagement in refining measures. While challenges such as climate change and anthropogenic pressures persist, the strategy reflects a commitment to holistic and adaptive management of marine ecosystems. Collaboration with international conventions like OSPAR enhances coherence and effectiveness in addressing these challenges at regional and broader scales.