Historical perspectives are relevant to marine conservation, yet rarely integrated into planning efforts. Marine conservation planning is concerned with measures that should be taken in the future. It usually focuses on mitigating anticipated adverse changes caused by current and future human activities, with the assumption that present conditions should be maintained. In this chapter, Natalie C. Ban, John N. Kittinger, John Pandolfi, Robert L. Pressey, Ruth Thurstan, Matthew J. Lybolt, and Simon Hart show that without incorporating historical data and analysis, such approaches, in the best case, will cause us to aim too low and, in the worst case, can result in inappropriate targets for planning and management. We review the role that historical perspectives can provide in marine conservation planning, highlight planning exercises in which this has occurred or has been discussed, and provide recommendations for researchers and planners. Using the systematic conservation-planning framework, we show that each planning stage benefits from a historical perspective, and we illustrate that failure to consider historical information reduces the effectiveness of marine conservation planning. We posit that historical perspectives may shift the conservation focus from restoring previous ecosystem states to recovering critical ecosystem functions that maintain resilience. Historical perspectives can change the conservation vision for a region, providing a window onto possibilities for the future.