Postpartum depression (PPD) affects 10-20% of women, with immigrant Latinas disproportionately affected. PPD prevention and treatment is limited among immigrant Latinas due to an array of structural and cultural factors, suggesting the need to deliver interventions outside of traditional healthcare settings. Virtual interventions have the potential to reduce barriers to mental health services for immigrant Latinas, but there is little research on the effectiveness of virtual interventions to reduce PPD symptoms. Mothers and Babies is an evidence-based group intervention based on principles of cognitive-behavioral therapy and attachment theory aimed at PPD prevention. Mothers and Babies was adapted for delivery via a virtual group format (Mothers and Babies Virtual Group; MB-VG), with a pilot study suggesting good feasibility and acceptability as well as improved mental health outcomes for immigrant Latinas. The proposed project is a Type 1 Effectiveness-Implementation randomized controlled trial among pregnant individuals and new mothers at risk for PPD based on elevated depressive symptoms and/or other established risk factors who are enrolled in early childhood programs across Maryland. A total of 300 women will be enrolled; 150 will receive MB-VG while 150 will receive usual family support services. The project aims to evaluate: 1) the effectiveness of MB-VG to reduce depressive symptoms, prevent onset of PPD, and improve parenting self-efficacy and responsiveness; 2) implementation of MB-VG; and 3) contextual factors influencing MB-VG effectiveness and implementation. Trained early childhood center staff will deliver MB-VG sessions, with intervention participants receiving virtual group sessions via Zoom using any electronic device (smartphone, tablet, laptop). Maternal self-report surveys are conducted at baseline, 1 week, 3 months, and 6 months post-intervention, with structured clinical interviews also conducted at 3- and 6-months post-intervention. The study is the first to deliver a virtual PPD preventive intervention to immigrant Latinas and to evaluate its impact. Given its virtual delivery modality, MB-VG can be easily replicated and scaled to other family support programs and settings serving immigrant Latinas. If effective and implemented broadly, more immigrant Latinas will receive mental health services and fewer will suffer the negative consequences associated with PPD.