Background <p>Subjective cognitive decline and mild cognitive impairment represent critical windows for intervention as early stages of dementia progression. Although digital health interventions have shown potential in enhancing cognitive performance and slowing cognitive decline, their clinical efficacy remains a subject of debate. This review aimed to systematically evaluate the impact of digital health interventions on cognition, emotion, functional ability, and quality of life in older adults with SCD and MCI.</p> Methods <p>We searched five databases for randomized controlled trials published until August 2025. Eligible studies involved adults aged 60&#xa0;years or older with SCD or MCI receiving a digital health intervention versus usual care or conventional non-digital interventions. This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Meta-analyses were conducted using random-effects models.</p> Results <p>Fifteen trials (<i>N</i> = 829) were included. The meta-analysis showed that digital health interventions significantly improved cognitive function (SMD = 0.387, 95% CI: 0.052–0.723<i>; I</i>^<i>2</i> = 66%) and functional ability (MD = 1.364, 95% CI: 0.937–1.790, <i>I</i>^<i>2</i> = 0.0%). However, no significant effects were observed for emotional status (SMD = -0.192, 95% CI: -0.405–0.021, <i>I</i>^<i>2</i> = 0.0%) or quality of life (MD = -0.660, 95% CI:-2.730–1.409, <i>I</i>^<i>2</i> = 0.0%). The small number of studies limited quantitative synthesis for specific cognitive domains.</p> Conclusion <p>Digital health interventions had been shown to improve global cognitive function and functional ability in older adults with SCD or MCI, but they did not appear to significantly affect emotional status or quality of life. However, these findings are based on evidence of limited methodological quality, and the results should be interpreted with caution. Further high-quality clinical trials are needed to confirm these effects and to clarify potential domain-specific cognitive benefits of digital health interventions.</p> Trial registration <p>Prospero Number: CRD420251155249.</p>