BackgroundHeat shock protein beta-1 (HSPB1) is a crucial biomarker for pathological processes in various cancers. However, the clinical value and function ofHSPB1in breast cancer has not been extensively explored. Therefore, we adopted a systematic and comprehensive approach to investigate the correlation betweenHSPB1expression and clinicopathological features of breast cancer, as well as determine its prognostic value. We also examined the effects ofHSPB1on cell proliferation, invasion, apoptosis, and metastasis.MethodsWe investigated the expression ofHSPB1in patients with breast cancer using The Cancer Genome Atlas and immunohistochemistry. Chi-squared test and Wilcoxon signed-rank test were used to examine the relationship betweenHSPB1expression and clinicopathological characteristics.ResultsWe observed thatHSPB1expression was significantly correlated with the stage N, pathologic stages, as well as estrogen and progesterone receptors. Furthermore, highHSPB1expression resulted in a poor prognosis for overall survival, relapse-free survival, and distant metastasis-free survival. Multivariable analysis showed that patients with poor survival outcomes had higher tumor, node, metastasis, and pathologic stages. Pathway analysis ofHSPB1and the altered neighboring genes suggested thatHSPB1is involved in the epithelial-to-mesenchymal transition. Functional analysis revealed showed that transient knockdown ofHSPB1inhibited the cell migration/invasion ability and promoted apoptosis.ConclusionsHSPB1may be involved in breast cancer metastasis. Collectively, our study demonstrated thatHSPB1has prognostic value for clinical outcomes and may serve as a therapeutic biomarker for breast cancer.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12885-023-10983-3.