The activation of Notch signalling induces epithelial‑mesenchymal transition (EMT), but this signalling pathway and its association with EMT in the context of cell motility in oral squamous cell carcinoma (OSCC) remains unclear. The present study aimed to investigate the role of the Notch signalling pathway and EMT in the metastatic potential of OSCC using 2 cell lines, Tca8113 and CAL27. The data demonstrated that zinc finger domain SNAI1 (Snail) knockdown by small interfering RNA decreased the expression of vimentin and increased the expression of epithelial cadherin (E‑cadherin). In addition, silencing Snail also significantly inhibited cell migration in the 2 OSCC cell lines. It was also identified that blocking Notch signalling with the g‑secretase inhibitor DAPT decreased the expression of the EMT markers Snail and vimentin and increased E‑cadherin expression, accompanied by a significant inhibition of cell migration in the 2 OSCC cell lines. These data clearly indicate that Notch signalling mediates EMT to promote metastasis in OSCC cells. Therefore, targeting Notch signalling and its association with EMT may provide novel insights into the mechanism of invasion and metastasis in OSCC and potential therapeutic interventions.