Aim Gestational diabetes mellitus (GDM) is the most common complication in pregnancy. This study aimed to investigate the potential mechanism and effects of long‐noncoding RNA maternally expressed 8 (lncRNA‐MEG8) in GDM. Methods Targeted interactions involving lncRNA‐MEG8 and miR‐296‐3p were initially predicted using starBase software and then confirmed using dual‐luciferase reporter gene analysis. The expression levels of lncRNA‐MEG8 and miR‐296‐3p in peripheral blood samples from patients with GDM were measured using reverse transcription‐quantitative polymerase chain reaction. Enzyme‐linked immunosorbent assay was used to evaluate the overall levels of insulin and insulin secretion. Additionally, MTT and flow cytometric methods were used to detect cell viability and apoptosis. Cell apoptosis‐associated proteins were determined by western blotting. Results Our results indicated that lncRNA‐MEG8 is a potential target of miR‐296‐3p. lncRNA‐MEG8 level was higher, whereas that of miR‐296‐3p was lower in patients with GDM than in healthy individuals. LncRNA‐MEG8‐siRNA promoted insulin content and secretion. Furthermore, MEG8‐siRNA increased cell viability and decreased apoptosis. However, these changes were reversed by an miR‐296‐3p inhibitor. Moreover, a miR‐296‐3p mimic had the same effect on INS‐1 cells as MEG8‐siRNA, as evidenced by enhanced insulin secretion, cell viability, and reduced apoptosis. Conclusion LncRNA‐MEG8‐siRNA promotes pancreatic β‐cell function by upregulating miR‐296‐3p.