Natural fibre (NF) is considered as the most available resource that exists in nature. Date palm trees (DPT) accounts for more than 2.8 million tons of waste annually, making it the most abundant agricultural biomass waste in the MENA region. Date palm fibre (DPF) extracted from DPT possesses great mechanical and physical characteristics which make them superior to other NFs in the MENA region. This study investigates the effect of DPF diameter size and loading content on both the mechanical and physical properties of DPF reinforced recycled polyvinyl chloride (RPVC) composite. The composites are developed using melt-mixing technique which is followed by compression moulding . The influence of the mechanical properties is investigated by evaluating the impact strength, tensile strength and flexural strength. Meanwhile the sieve analysis , thickness swelling (TS), moisture content (MC) and water absorption (WA) characteristics are evaluated. Composite microstructures are examined using optical microscopy to investigate the interfacial bonding between DPF and RPVC matrix. Results showed that at 40 wt% DPF, the TS, MC and WA were the highest demonstrating an increase of 1.57%, 1.76%, and 10.80%, respectively. The flexural strength, tensile strength and impact strength decreased as the loading content increased showing maximum reduction at 40 wt% loading, varying depending on DPF geometry. Although the results demonstrated a decrease in mechanical properties and an increase in physical properties as DPF loading increased depending on DPF geometry, the results indicate a great potential that the developed technologies could be industrialised under the waste management scheme for non-structural applications. • Utilising DPF agricultural biomass waste into developing sustainable composites. • Optimising DPF/RPVC composites with designing DPF geometry and concentration. • Establishing correlation of DPF/RPVC property and DPF parameters. • Structure and interfacial bonding characteristics of DPF/RPVC composites.