Introduction Suicide is a serious public health concern worldwide. Current psychological interventions targeting suicidal ideation and behavior are, however, limited and often lack convincing empirical support. Future‐Oriented Group Training (FOGT) targets crucial aspects of the suicidal process, thus possibly offering a promising intervention for suicidal ideation. This study aimed at investigating the short‐term and long‐term effects of FOGT on suicidal thoughts and related variables. Methods A randomized controlled trial was conducted, comparing the intervention group (FOGT + treatment as usual (TAU)) to a control group (TAU) at pre and posttreatment and at a 12‐week follow‐up. Suicidal ideation was the primary outcome, while depressive symptoms, hopelessness, defeat, entrapment, worrying, and the ability for future‐oriented thinking were secondary outcomes. Results When compared to the control group, the intervention group showed significant decreases in worrying at posttreatment and significant increases in future‐oriented thinking at follow‐up. Pre‐post analyses within the intervention group showed significant small‐to‐medium effects for primary as well as most secondary outcomes. Changes in suicidal ideation, depression, hopelessness, and future‐oriented thinking remained significant at follow‐up. Conclusion This study provides promising empirical evidence for the use of FOGT for individuals with suicidal ideation.