Krüppel-like factor 1 (KLF1) is a transcription factor that exhibits promoting effect in cervical cancer, but its correlation with gastric cancer (GC) has not been reported yet. In this study, we explored the role and potential mechanism of KLF1 in GC progression by using a series of experimental methods including RT-qPCR, Western blot, CCK-8 assay, EdU staining, and cell cycle analysis. KLF1 was found to be elevated in GC tissues (n=415) compared with the normal tissues by applying UALCAN to analyze datasets from The Cancer Genome Atlas (TCGA). The upregulation of KLF1 was also validated in GC cell lines. Functional studies proved that RNA interference-mediated silencing of KLF1 inhibited GC cell growth, as evidenced by the decreased cell viability, DNA synthesis, and arrested cell cycle in G1 phase. Moreover, KLF1 knockdown exerted the inhibitory effects on cell migration and invasion as well as the epithelial-mesenchymal transition (EMT) in GC cells. Conversely, overexpression of KLF1 had the opposite effects on GC progression. Furthermore, we proved that the activation of Wnt/β-catenin pathway was markedly inhibited by KLF1 knockdown and promoted by KLF1 overexpression. The blockade of Wnt/β-catenin pathway rescued the effects of KLF1 overexpression. These results suggested that KLF1 promoted the growth, migration, invasion, and EMT process in GC cells, and this promotion was achieved by activating the Wnt/β-catenin pathway. This work will be helpful for searching the potential therapeutic targets for treatment of GC.