<p>Growing concerns over industrial energy consumption and environmental sustainability have intensified the need for energy-efficient manufacturing. This paper provides a comprehensive review of energy reduction strategies for machine tools, aiming to bridge academic research with practical applications. We first analyze the fundamental energy consumption characteristics of machine tools, emphasizing the significant impact of auxiliary components and non-processing states as defined by the ISO 14,955 standard. Subsequently, a systematic review and statistical analysis of existing literature are presented, categorizing strategies into three distinct levels: component, process, and operation. At the component level, strategies focus on the energy reduction of main and auxiliary components. Process-level reduction strategies, the most widely researched area, offer substantial savings through energy-efficient process planning, tool path optimization, and cutting parameter optimization. Operation-level strategies include data-driven eco-operation of individual machine tools and energy-aware multi-machine scheduling. Additionally, a review of the best industrial practices is conducted to examine the gap between these academic strategies and their current industrial adoption. Finally, the review proposes future research directions, highlighting the need to broaden research on energy-consuming components, improve the industrial implementation of these reduction strategies, and validate energy savings in real-world industrial applications to accelerate the transition toward sustainable machining.</p>