Diosgenyl saponins possess a variety of biological functions. Herein, we demonstrate a new type of diosgenyl saponin derivatives that inhibit cellular proliferation of oral squamous cell carcinoma (OSCC) cell lines. Thereafter, we analyzed these cells’ expression of apoptosis-related proteins. Crucial proteins that participate in apoptosis regulation including caspases 8, 9, and 3, and cleaved Bid were activated and upregulated accompanied by increased concentrations of diosgenyl saponins. Meanwhile, Bcl-2 was downregulated and mitochondrial membrane potential decreased. In our mice model of OSCC, compound 1 showed potent inhibition of solid tumor growth and salient antitumor activity. Diosgenyl β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside might induce OSCC cell line apoptosis through extrinsic and intrinsic pathways, and might provide a mechanistic background for the development of this new type of diosgenylsaponin derivatives into anti-oral cancer agents against OSCC.