Suicide prevention programs delivered in school settings have been shown to reduce suicide attempts and ideation among adolescents. School-based digital interventions targeting at-risk youth are a promising avenue for suicide prevention, and some evidence has shown that blending digital and face-to-face components may improve the effectiveness. However, further evidence on its acceptability, feasibility, and effectiveness is needed, especially in Latin America, where mental health support is limited. Reframe-IT is an internet-based Cognitive Behavioral Therapy (CBT) program to reduce youth suicidal ideation in school settings. We created four complementary face-to-face CBT sessions and, through a pilot study, tested the acceptability, feasibility, and effectiveness of a blended intervention (Reframe-IT +) in adolescents (N = 52) from 6 public schools in Chile, randomized into two groups: Reframe-IT + (N = 33) and Control (N = 19). We found that the intervention was acceptable and feasible, with high degrees of satisfaction and adherence. We also observed a significant reduction in suicidal ideation and depressive symptoms in the intervention group compared to the control group at post-intervention. Our results suggest that the Reframe-IT + could be delivered as a suitable, acceptable, and effective intervention to reduce suicide ideation in adolescents in school settings. Further research is needed to confirm these preliminary results.