Cervical dysfunction, a major contributor to preterm labor and neonatal mortality, remains poorly understood due to the absence of physiologically relevant human models. Here, we show that a microfluidic human Endocervix Chip lined by primary endocervical epithelium interfaced with stromal cells and cultured under pregnancy-like hormonal conditions recapitulates key aspects of the biology of the endocervix, including formation of a mucus plug-like structure with antimicrobial properties. Culturing a dysbiotic cervico-vaginal microbiome on-chip increased secretion of pro-inflammatory cytokines observed in patients with preterm labor and enhanced production of matrix metalloproteinases (MMPs) that degrade stromal extracellular matrix (ECM). Perfusion with inflammatory cytokines at clinically relevant concentrations altered cervical mucus composition, upregulated prostaglandin-endoperoxide synthase 2 expression, increased MMP secretion, and reduced collagen production, which together drive dissolution of the stromal ECM and promote cervical ripening. Addition of circulating peripheral blood mononuclear cells (PBMCs) amplified these effects. Administration of a clinically approved drug for prevention of preterm labor that the Food and Drug Administration (FDA) recently deemed ineffective was also found to be inactive in the chip, while an approved therapeutic antagonist of the IL-1 receptor successfully protected against cervical dysfunction in this model. These findings demonstrate that IL-1 acts directly on human cervical tissues to promote changes associated with initiation of labor and that primary human endocervix chips may represent a useful preclinical model for studies on cervical dysfunction associated with preterm birth.