The article calls for a shift in organizational theory towards prospective theorizing, which is defined as a future-oriented approach focused on imagining desirable futures. This shift involves two key dimensions: from projection to imagination and from values-neutral to values-led theorizing. The authors propose four modes of theorizing the future: projected factual futures, imagined (counter-)factual futures, projected desirable futures, and imagined desirable futures. To facilitate this shift, they suggest specific practices along the inputs, throughputs, and outputs of theorizing, emphasizing the importance of imaginative data, thought experiments, and values-led data. The article also introduces the concept of "speculative rigor" to ensure that prospective theorizing is scientifically rigorous and generative. Overall, the authors argue that prospective theorizing can add to the plurality of organizational theories and contribute to impactful and engaged scholarship.The article calls for a shift in organizational theory towards prospective theorizing, which is defined as a future-oriented approach focused on imagining desirable futures. This shift involves two key dimensions: from projection to imagination and from values-neutral to values-led theorizing. The authors propose four modes of theorizing the future: projected factual futures, imagined (counter-)factual futures, projected desirable futures, and imagined desirable futures. To facilitate this shift, they suggest specific practices along the inputs, throughputs, and outputs of theorizing, emphasizing the importance of imaginative data, thought experiments, and values-led data. The article also introduces the concept of "speculative rigor" to ensure that prospective theorizing is scientifically rigorous and generative. Overall, the authors argue that prospective theorizing can add to the plurality of organizational theories and contribute to impactful and engaged scholarship.