This study investigates the potential of ozonolysis pretreatment on oil palm frond (OPF) for enhancing total reducing sugar (TRS) recovery. The OPF is pretreated by ozonolysis prior to two-step acid hydrolysis. The effect of ozonolysis pretreatment on the physico-chemical properties of OPF is scrutinized followed by the effect of process parameters on lignin degradation and TRS recovery. The presence of lignin-rich and cellulose-rich fractionates are proven by TGA. The XRD reveals crystallinity after pretreatment is increases while crystal size reduces indicating the removal of amorphous lignin region. The structure of OPF is disrupted during the pretreatment revealing the cellulose rosette structure in treated OPF as shown by FeSEM. Ultimately, TRS recovery increases up to 62.3 % with 90 % lignin degradation. This testifies ozonolysis is pertinent for enhancing sugar yields in acid hydrolysis. Among the process parameters, OPF particle size is the most significant followed by reaction time, moisture content, and ozone flowrate. The findings of this work contribute to new information about the pretreatment of biomass by ozonolysis.