The ocean, our life support system, is central to the intricate relationship between climate and biodiversity. Ocean-based solutions have the potential to deliver on both the Global Biodiversity Framework and Paris Agreement, acting as a connector across the Biodiversity and Climate Conventions. However, despite growing calls from the international community for more policy coherence and alignment, synergies between the two regimes have not been realised. This separation is reflected in national strategies, namely National Biodiversity Strategies and Action Plans (NBSAPs) and Nationally Determined Contributions (NDCs). As a result, policies are developed in silos, addressing either biodiversity or climate goals, without systematically considering the interconnections between the two. Ocean-based solutions have a key role to play in leveraging these synergies, weaving a “blue thread” between national biodiversity and climate strategies.