Claudins (CLDNs) play a crucial role in regulating the permeability of epithelial barriers and can impact tumor behavior through alterations in their expression. However, the precise mechanisms underlying the involvement of CLDNs in breast cancer progression remain unclear. This study aimed to investigate the role of CLDN11 in breast cancer progression. Utilizing the TCGA database and clinical specimens from breast cancer patients, we observed reduced expression of CLDN11 in tumor tissues, which correlated with poor prognosis in breast cancer patients. In vitro, silencing of CLDN11 enhanced the proliferative and migratory characteristics of breast cancer cell lines MCF-7 and MDA-MB-231. Mechanistically, CLDN11 deficiency promoted the upregulation of Forkhead Box M1 (FOXM1) by activating the hedgehog signaling pathway, thereby sustaining tumor progression in breast cancer. In vivo, blockade of hedgehog signaling suppressed the tumor progression induced by CLDN11 silencing. Our study highlights the significance of the CLDN11/FOXM1 axis in breast cancer progression, suggesting CLDN11 as a potential diagnostic indicator and therapeutic target for clinical therapy.