Digital health technologies have expanded tremendously in the last two decades, creating an emerging research and clinical field. They are regarded as cost-effective, and their use in healthcare is prioritized by many countries. However, the constant evolution of these technologies has led to an abundance of related literature. Thus, we conducted an umbrella review to identify and characterize digital supportive care interventions for patients with cancer and their relatives. A preregistered umbrella review was conducted (PROSPERO registration number CRD42022333110). Five databases were searched (Embase, PsycINFO, PubMed, CINAHL, and the Cochrane Library). To be considered, studies had to be systematic reviews or meta-analyses, be performed on pediatric or adult patients with cancer or survivors or their relatives, report results on web-based or app-based supportive care interventions, and measure psychological, functional, or behavioral variables or quality of life related to cancer. The methodological quality of the studies was assessed using the AMSTAR-2 tool. Twenty eligible studies were identified. Most of the included studies reported results from adult patients with cancer. Globally, digital interventions were shown to be effective for physical activity in patients with cancer but had mixed results regarding emotional outcomes and quality of life. Additionally, a lack of methodological quality was noted for most of the included reviews. Digital supportive care interventions could be an effective tool in cancer care for some outcomes. Recommendations have been formulated for further research in this field using adapted methodologies for the development of digital health interventions.