We performed a meta-analysis to investigate the effects of high-intensity interval exercise (HIIE) as compared to moderate-intensity exercise (MIE) and a control condition (CON) on postprandial glucose (PPG) and insulin (PPI) responses. PubMed, Web of Science, and Scopus were comprehensively searched to identify relevant studies until October 2021. Separate analyses were conducted for HIIE versus MIE and HIIE versus CON. A total of 30 studies comprising 36 intervention arms and involving 467 participants (350 adults) were included in the meta-analysis. HIIE reduced PPG and PPI when compared with CON. Based on subgroup analyses, reductions in PPG and PPI were significant for both children and adult participants, as well as for healthy participants and participants with metabolic disorders, with larger effects in those with metabolic disorders. There were no significant differences between HIIE and MIE for PPG or PPI. However, when comparing studies matched for total work performed, HIIE was more effective for decreasing PPG as compared with MIE. HIIE is effective for reducing PPG and PPI in both children and adult participants, particularly in those with metabolic disorders. In addition, HIIE has superior effects for reducing PPG as compared with MIE, when equivalent work was performed at both intensity levels.