INTRODUCTION: Task-shifting and task-sharing strategies show promise for managing chronic diseases especially in low-income and middle-income countries (LMICs), though their effectiveness in multimorbidity management remains unclear. This study synthesised evidence on task-shifting and task-sharing strategies globally and assessed the impact on core health outcomes in multimorbidity management. METHODS: We conducted a systematic review and meta-analysis of global studies evaluating task-shifting and sharing interventions for individuals with multimorbidity. Six databases, including PubMed, Embase, Web of Science, Ovid (Medline), CINAHL and Cochrane Library, were searched for studies reporting the core outcomes of multimorbidity management in quality of life, mortality, hospitalisation, emergency department visits and symptoms of depression and anxiety. Random-effects models were used to calculate pooled effect sizes with heterogeneity assessed through subgroup and meta-regression analyses. RESULTS: From 8471 records, 36 studies from 14 countries were included, with only 5 conducted in LMICs. Twenty-one studies, encompassing 20 989 participants, were eligible for meta-analysis. More than half of the studies involved nurses as delegates, with some sharing the tasks with health professionals and about 10% of studies involved non-health professionals, including community healthcare workers as delegates to share the responsibility in caring for individuals with multimorbidity. Most studies were multicomponent, with 16.7% addressing all guideline-recommended aspects of multimorbidity management. By pooling the findings, task-shifting and task-sharing interventions were associated with a 27% reduction in mortality (OR: 0.73, 95% CI: 0.55 to 0.97, I²=0%), a modest improvement in quality of life (standardised mean difference (SMD): 0.1, 95% CI: 0.03 to 0.17, I²=47%) and reduced symptoms of depression (SMD: 0.27, 95% CI: -0.52 to -0.02, I²=90%), but showed no significant effect on hospitalisation, emergency visits or anxiety-related symptoms. CONCLUSIONS: Some evidence, although limited in existing research, indicates the great potential of task-shifting and task-sharing strategies in supporting management of multimorbidity. Further research is needed to optimise and adopt these interventions, particularly in LMICs where evidence remains scarce. PROSPERO REGISTRATION NUMBER: CRD42024526845.