The European Commission’s so-called ‘Winter Package’ of energy legislation will provide the framework for energy policy in the European Union for many years to come. It contains proposals for a whole range of energy-related reforms including energy markets, energy infrastructure, renewable energy, climate policy, and energy demand. In this paper, we carry out a preliminary review of the proposals and what they mean for energy efficiency. The European Union has adopted the principle of ‘Efficiency First’ through the launch of the Energy Union Communication in February 2015. We assess the extent to which the Winter Package keeps the promise of putting energy efficiency first. More specifically, we analyse the revised Energy Efficiency Directive (EED), the Energy Performance in Buildings Directive (EPBD), the Directive on common rules for the Internal Energy Market for electricity (IEM), the Regulation on the electricity market, and the Regulation on Governance of the Energy Union. We conclude that, while many improvements are proposed across the different pieces of legislation, the Winter Package falls short of comprehensively reflecting the Efficiency First principle. The paper provides a number of concrete policy recommendations in order to incorporate the Efficiency First principle more fully into the proposed set of European energy legislation.