Background: Suicide among adolescents has long been linked to symptoms of depression. However, limited research has examined the potential buffering effect of hope on the relationship between depression and suicide attempts. Methods: To test the effect of hope on the positive relationship between depression and suicide attempts, we used data (N = 502 adolescents) from youth ages 12-18 collected as part of the 2018 Healthy Youth Survey in the State of Washington. Based on hope theory, we hypothesized a "buffering" form of moderation, with the presence of greater hope weakening the positive relationship between depression and suicide attempts. In other words, with higher hope, adolescents reporting depressive symptoms are less inclined to attempt suicide. Results: Testing the moderating effect of hope via bootstrap resampling (N = 5000), the results indicated adolescents' hope levels indeed buffered the relationship between depressive symptoms and self-reported suicide attempts. To wit, when adolescents' hope was low, there was a significant, robust, and positive relationship between depressive symptoms and suicide attempts (b = 0.2644, 95% CI [0.1604, 0.3683], t = 5.0, p < 0.001). However, when adolescents' hope was high, there was no longer a significant relationship between depressive symptoms and suicide attempts (b = 0.0304, 95% CI [-0.997, 0.1605], t = 0.4590, p = 0.65). Conclusion: The buffering effect of hope was validated in a second, larger sample (n = 9308) of adolescents. This result suggests the potential utility of hope theory-based interventions to assist depressed adolescents reduce their likelihood of suicide.