Objective To explore the role and mechanism of zinc finger protein 36 like 1 (ZFP36L1) in breast cancer. Methods Sixty breast cancer patients were enrolled in the study. Immunohistochemistry was performed to evaluate the ZFP36L1 expression. Clinicopathological parameters were observed. MCF-7 cells were transfected with overexpressed ZFP36L1 plasmid. The viability of MCF-7 cells was assayed by the 5-ethynyl-2-deoxyuridine (EdU) and MTS assay. The invasion of MCF-7 cells was assessed by TranswellTM assay. Western blot analysis was used to detect the expression of β-catenin, vimentin, E-cadherin, signal transducer and activator of transcription 3 (STAT3), and phosphorylated STAT3 (p-STAT3). Results ZFP36L1-low expression has been found to be associated with poor prognosis in patients with breast cancer. Moreover, ZFP36L1 overexpression inhibited cell proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) in vitro. Accordingly, the expression of STAT3 and p-STAT3 increased significantly. Conclusion ZFP36L1, as a cancer suppressor gene, inhibits cell proliferation, invasion, and migration through EMT and STAT3 signaling pathway.