BACKGROUND: Mental health plays a key role across the cancer care continuum, from prognosis and active treatment to survivorship and palliative care. Digital health technologies offer an appealing, cost-effective tool to address psychological needs. OBJECTIVE: This umbrella review aims to summarize and evaluate the available evidence on the efficacy of digital health interventions for improving mental health and psychosocial outcomes for populations with cancer. METHODS: Literature searches were conducted in Embase, PsycINFO, PubMed, CINAHL, the Cochrane Library, and Web of Science from their inception to February 4, 2024. Systematic reviews (with or without meta-analysis) investigating the efficacy of digital health interventions for psychosocial variables in patients with cancer were included. Quality was assessed using the Assessing the Methodological Quality of Systematic Reviews-2 tool. RESULTS: In total, 78 systematic reviews were included in this review. Among diverse delivery modalities and types of digital interventions, websites and smartphone apps were the most commonly used. Depression was the most frequently addressed, followed by quality of life, anxiety, fatigue, and distress. The qualities of the reviews ranged from critically low to high. Generally, despite great heterogeneity in the strength and credibility of the evidence, digital health interventions were shown to be effective for mental health in patients with cancer. CONCLUSIONS: Taken together, digital health interventions show benefits for patients with cancer in improving mental health. Various gaps were identified, such as little research specifically focusing on older adult patients with cancer, a scarcity of reporting high-precision emotion management, and insufficient attention to other certain mood indicators. Further exploration of studies with standardized and rigorous approaches is required to inform practice. TRIAL REGISTRATION: PROSPERO CRD42024565084
https://tinyurl.com/4cbxjeh9.