GRWD1 is a member of the WD repeat protein family that is over-expressed in various cancer cell lines and associated with poor prognosis in patients with cancer. However, its biological function and mechanism in non-small cell lung cancer (NSCLC) remain unclear. In this study, we aimed to elucidate the role of GRWD1 in NSCLC. Immunohistochemistry on tumor specimens from 170 patients showed that GRWD1 is highly expressed in NSCLC tissues and positively correlated with tumor size, lymph node metastasis, and P-TNM stage, but negatively correlated with differentiation and prognosis. We found that GRWD1 promotes cell colony formation by affecting the expression of Cyclin B1, CDK1, and p27 and inducing G2/M transition. GRWD1 was also found to stimulate cell migration through RhoA, RhoC, and CDC42, and induce epithelial-mesenchymal transition by affecting the expression of E-cadherin, N-cadherin, Vimentin, Snail, Zeb1, and ZO-1. Our results indicated that the GRWD1 can activate the Notch signaling pathway by affecting the Notch intracellular domain and promoting the expression of Hes1. Our use of DAPT to suppress Notch signaling confirmed that GRWD1 promotes the progression of NSCLC through the Notch signaling pathway and may be a potential prognostic biomarker and therapeutic target for this disease.