IANOS is a Horizon 2020 project at the forefront of addressing the complex energy transition challenges by using islands as testbeds for innovation. This initiative has established two ‘Lighthouse Islands’ in Ameland (the Netherlands) and Terceira (Portugal). IANOS’s Energy Transition Strategy not only develops practical innovations but also implements them within the social fabric of these islands. Key focus areas include “Energy efficiency and grid support”, “Decarbonization”, and “Empowering local communities”. These strategies are replicated across three EU ‘Replication Islands’, namely, Lampedusa (Italy), Nisyros (Greece) and Bora Bora (French Polynesia).