Students at risk of suicide can be identified effectively through school-based prevention programs such as Signs of Suicide (SOS), which incorporate both psychoeducation and screening components. Prior research has focused on high school students; however, there is limited research in middle schools, and even less is known of school staff's responsiveness to these programs. The current study evaluated the implementation of SOS with students at two U.S. middle schools (N = 2,537; 49% female) and through a treatment evaluation survey completed by school implementation staff (N = 26; 89% female). Nearly 20% of students emerged as at risk for suicide; risk was significantly higher among females, sixth graders, students with lower socioeconomic status, and students eligible for special education or accommodation plans. Most staff rated SOS as an acceptable program, and qualitative feedback regarding strengths and barriers is described. These findings advance practical knowledge for effectively implementing school-based suicide prevention programs and may guide school psychologists in advocating for and implementing such interventions.