The Special Issue "Shaping Tomorrow's Arctic," explores the past, present, and future of the Arctic. Decisions made now are fundamentally shaping the multiple Arctics of 2050. This collection of research articles, reviews, and commentaries address Arctic futures from local, national, regional, and international perspectives, spanning a wide range of disciplines and including perspectives from Indigenous and early career, as well as senior scholars. Special Issue authors address questions such as: In looking forward, what can we learn from past experiences, as well as from recent responses to change? What steps should we be taking now to lay the foundation for equitable, just and inclusive Arctics? How might futures differ for multiple Arctic populations, economies, cultures, and governance? The resulting scope of "Shaping Tomorrow's Arctic" extends from the need to restructure approaches to societal and economic equity, to ways to build capacity for adaptation, knowledge co-production for resilient futures, and Arctic-global repercussions. The articles present enduring foundations for future research and decision-making that can guide us through this complexity, to think ahead, co-produce approaches, and try to make the better choices-not just for us and now-rather systematically, for the most vulnerable, and into the future. We know our prior paths have led us to the uncertain present and a perilous future. It is time to make intentional choices to shape thriving Arctic futures.