Background Globally, emergency departments (EDs) are overcrowded and unable to meet an ever-increasing demand for care. The aim of this study is to comprehensively review and synthesise literature on potential solutions and challenges throughout the entire health system, focusing on ED patient fow. Methods An umbrella review was conducted to comprehensively summarise and synthesise the available evidence from multiple research syntheses. A comprehensive search strategy was employed in four databases alongside government or organisational websites in March 2023. Gray literature and reports were also searched. Quality was assessed using the JBI critical appraisal checklist for systematic reviews and research syntheses. We summarised and classifed fndings using qualitative synthesis, the Population-Capacity-Process (PCP) model, and the input/ throughput/output (I/T/O) model of ED patient fow and synthesised intervention outcomes based on the Quadruple Aim framework. Results The search strategy yielded 1263 articles, of which 39 were included in the umbrella review. Patient fow interventions were categorised into human factors, management-organisation interventions, and infrastructure and mapped to the relevant component of the patient journey from pre-ED to post-ED interventions. Most interventions had mixed or quadruple nonsignifcant outcomes. The majority of interventions for enhancing ED patient fow were primarily related to the ’within-ED’ phase of the patient journey. Fewer interventions were identifed for the ’post-ED’ phase (acute inpatient transfer, subacute inpatient transfer, hospital at home, discharge home, or residential care) and the ’pre-ED’ phase. The intervention outcomes were aligned with the aim (QAIM), which aims to improve patient care experience, enhance population health, optimise efciency, and enhance staf satisfaction. Conclusions This study found that there was a wide range of interventions used to address patient fow, but the efectiveness of these interventions varied, and most interventions were focused on the ED. Interventions for the remainder of the patient journey were largely neglected. The metrics reported were mainly focused on efciency measures rather than addressing all quadrants of the quadruple aim. Further research is needed to investigate and enhance the efectiveness of interventions outside the ED in improving ED patient fow. It is essential to develop interventions that relate to all three phases of patient fow: pre-ED, within-ED, and post-ED. [ABSTRACT FROM AUTHOR]