As the archival profession is inextricable from future-focused thinking, sustainable preservation must be incorporated into archival practice. Sustainable thinking considers the economic, environmental, social, and cultural needs of both present and future generations, without privileging one factor over another. This article investigates the existing literature on sustainable preservation practices in archives. Sustainability presents a challenge to the archival mission. Becoming more sustainable begins with changing practices, which requires investing time, money, and energy to learn new information. The imperative to provide care for cultural resources is an argument for proceeding with caution. Nevertheless, the reality of the climate crisis and an ever-growing body of evidence from the archives field suggest that archives can and should adopt more sustainable practices. Research indicates that preservation goals may be more effectively met through sustainable practices, leading to more reliable preservation environments and financial savings for the institution as a result of reduction in energy use. This article identifies opportunities for action archives can take to become more sustainable through building design, learning from cultural preservation traditions, rethinking the role of archivists, and reconsidering the impact of practices, both small and large. In the 1980s, Hugo Stehkämper drew attention to principles for natural air-conditioning reliant upon building design, but civilizations have been developing procedures for preserving cultural heritage materials for centuries prior to the advent of so-called modern technology. In the current century, archives, libraries, and museums are continuing to discover a multitude of effective sustainable methods. Drawing upon decades of study, successes, and failures will allow archivists to assess and rethink practices.