This report examines the role of local and regional authorities (LRAs) in implementing the Fit for 55 package. The Fit for 55 package revises major European Union (EU) energy directives, such as the Energy Performance of Buildings Directive (EPBD), the Renewable Energy Directive (RED) and the Energy Efficiency Directive (EED). These all impose new obligations on LRAs, including stricter requirements for building renovations, expanded mandates for integrating renewable energy at local level, and binding energy efficiency targets for public sector buildings. In addition, LRAs are required to establish local heating and cooling plans, facilitate renewable energy communities, and ensure the implementation of municipal and regional energy transition strategies. The package also highlights the role of new and existing EU funds as key sources for financing the energy transition, including the Social Climate Fund, the European Regional Development Fund (ERDF), the Just Transition Fund (JTF) and Horizon Europe.