Objectives: This study aimed to evaluate the effectiveness of interventions in reducing loneliness among community-dwelling older adults. Design: A network meta-analysis (NMA) and systematic review. Setting and participants: Interventional studies were included if they contained original quantitative data on interventions to reduce loneliness among community-dwelling older adults. Qualitative studies were included if they contained views on loneliness coping strategies or intervention evaluation. Methods: Six English databases and 3 Chinese databases were searched for studies published before August 2023. We extracted mean and standard deviation for the NMA to examine the overall effectiveness and efficacy of different interventions on loneliness. Thematic analysis was used to derive perspectives on coping strategies to mitigate loneliness. Results: Forty-six quantitative studies with 6049 participants and 40 qualitative studies with 1095 participants were included in the analysis. The pooled effect size was large and significant [standardized mean difference (SMD), -0.95; 95% CI, -1.32 to -0.58; P < .001], indicating a strong effect of interventions in reducing loneliness. Subgroup analyses revealed significant differences in effect sizes by study region and health risk. Results of the NMA suggested interventions seem to be most effective when having psychosocial interventions as the content, a combination of individual and group as the delivery mode, and a mixture of face-to-face and online methods as the contact mode. Findings of the qualitative synthesis revealed 2 main dimensions of activities for reducing loneliness, including delivery modes (individual or group or combination) and settings (indoor or outdoor or combination). Strategies for coping with loneliness at the social, cognitive, and behavioral levels were also identified. Conclusions and implications: The present study identified the most effective components of loneliness interventions in reducing loneliness among older adults. Findings offer important insights for practice and policy-making on potential strategies that can be used to reduce loneliness among community-dwelling older adults.