COVID-19 has not only triggered a high risk of mental health problems but brought tremendous changes in the structure of social support. To synthesize the existing literature and examine the impact of social support on anxiety and depression during COVID-19, scoping review and meta-analytic approaches were adopted. Six databases were searched from 2020 to 2022. Random effects models were used and the pooled correlations (mean r and mean ρ) were estimated. Homogeneity was assessed using Q and I² tests. Subgroup analyses were conducted. Meta-analysis of both cross-sectional and longitudinal studies showed significant estimated correlations among social support, anxiety and depression (mean ρ = -0.30, 95% CI = [-0.333, -0.255]; mean ρ = -0.27, 95% CI = [-0.370, -0.281]). Validating these results across ages, occupations, and regions is necessary. Moreover, only 31.67% of studies identified social support as a single independent variable while the remaining explored a mediating or moderating role or as one of the multiple independent variables. Besides, the results regarding the mediating/moderating effect of social support were inconsistent. Our findings suggest that more studies are expected to further clarify the role played by social support in its associations with depression and anxiety.