Prior research indicates that visual self-distancing enhances adaptive self-reflection about negative past events (Kross & Ayduk, 2011). However, whether this process is similarly useful when people reflect on anxiety-provoking future negative experiences, and if so, whether a similar set of mechanisms underlie its benefits in this context, is unknown. Here we addressed these questions using a combination of experimental and individual difference methods with adults and adolescents (total N = 2,344). In Studies 1 and 2, spontaneous self-distancing predicted less anxious emotional reactivity among adults and adolescents. This effect was mediated by differences in how vividly participants imagined a future anxiety-provoking event. Study 3 provided causal evidence in an adult sample: Adopting a self-distanced (vs. self-immersed) perspective when reflecting on a future stressor led to lower levels of anxiety as well as lower imagery vividness. Consistent with Studies 1 and 2, reductions in imagery vividness mediated the emotion regulatory benefits of self-distancing. A meta-analysis of all three studies further confirmed these findings across samples. Thus, the current studies extend previous research on the benefits of self-distancing to future stressors. In addition, they highlight a novel mechanism for this relation: imagery vividness. (PsycINFO Database Record (c) 2019 APA, all rights reserved).