<P><B>Abstract</B></P> <P>In this work, the feasibility of ethanol production from waste pizza (WP) by enzymatic hydrolysis and fermentation was investigated. The effects of enzyme volumes (0.02-0.08 mL/L) and WP mass ratios (50−160 g/L) on the performance of enzymatic hydrolysis and ethanol fermentation were also examined. It was observed that the lowest enzyme volume (0.02 mL/L) could completely hydrolyze WP with mass ratio of 50 g/L. The reducing sugar (RS) increased obviously with increasing of WP mass ratio from 50 g/L to 160 g/L when the enzyme volume of 0.02 mL/L was applied. The WP hydrolysate was utilized as substrate for bio-ethanol production with the highest cumulative ethanol production of 27.58 g/L and ethanol yield of 0.292 g/g WP, respectively. To our knowledge, this is the first study to report ethanol production from WP by enzymatic hydrolysis and fermentation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Feasibility of using waste pizza for ethanol fermentation was examined. </LI> <LI> Enzymatic hydrolysis of WP by α-amylase could be completed within 50 min. </LI> <LI> The total power consumed for the whole bio-process was 1.1 kW⋅h. </LI> <LI> The highest ethanol yield of 0.292 g/g WP was obtained. </LI> <LI> This is the first study to report bio-ethanol production from WP. </LI> </UL> </P>