This observational cohort study examined the relationships between actual and perceived R/S change at 12 months post cancer diagnosis with depression, anxiety, and perceived growth 6 months later. Older adult military veteran cancer survivors (n = 111) completed self-report surveys at 6, 12, and 18 months post cancer diagnosis. Perceived R/S change was assessed at 12 months postdiagnosis with “Have your religious or spiritual beliefs changed as a result of your cancer” (more R/S, less R/S, other). Actual R/S change was assessed at 6 and 12 months postdiagnosis on a single item, “I have faith in God or a Higher Power” (no, somewhat, yes). A notable minority reported perceived (18.9%) and actual (14.4%) change. Greater perceived R/S change predicted more severe symptoms of depression and anxiety and greater perceived growth at 18 months postdiagnosis; perceived growth was positively associated with anxiety. Cancer survivors who report R/S changes may benefit from spiritual and/or psychological support.