Under the European Green Deal’s bold EU climate and energy policies, every single EU citizen will be directly affected. As part of the commitment to ‘leave no one behind’, it is vital to mitigate and alleviate any excessive or undesirable outcomes that could disproportionately impact specific gender or social groups. This study, commissioned by the European Parliament’s Policy Department for Citizens’ Rights and Constitutional Affairs at the request of the FEMM Committee, assesses whether a gender dimension has been incorporated in the initiatives proposed under the Fit for 55 package and whether a gender-sensitive approach was used in its formulation. Examples are given of good practice for gender mainstreaming in energy and climate policy. Recommendations are made to close identified gender gaps in policies and processes.