<p>Date palm fibers (DPFs) have been effectively utilized as reinforcements in polymer matrices to enhance their properties. In this study, DPFs and nanoclays were treated with an amino functional silane coupling agent to enhance their compatibility with polybenzoxazine (PBz) and epoxy resin (EP) thermosets. The inherent instability in thermal properties of PBz and EP thermosets, attributed to high brittleness, led to the development of DPF-reinforced polybenzoxazine and epoxy composites. The impact of DPFs loading on thermal properties was investigated, revealing significant enhancements in thermal properties and char yields with varying organoclay loadings, indicating the effectiveness of the latter in the nanocomposites. Furthermore, the treated composites exhibited improved interfacial adhesion, as evidenced by SEM analysis of the surface hybrid, showcasing excellent interfacial bonding. This study not only explored the potential of utilizing abundant agricultural waste, specifically DPFs, for environmental sustainability and sustainable development but also delved into the enhancement of thermal stability through the incorporation of organosilane-treated DPFs and organoclay nanofillers in EP and PBz matrices. Characterization techniques such as FTIR and SEM confirmed the successful enhancement of DPFs’ hydrophobicity and surface roughness post-treatment, contributing to improved fiber-matrix adhesion. These results underscore the importance of the interfacial adhesion and aminosilane treatment for achieving desired properties in natural fiber-reinforced composites, paving the way for more environmentally friendly composite materials.</p> Graphical Abstract <p></p>