The most significant challenge that the world is currently facing is the development of beneficial industrial applications for solid waste. A novel strategy was implemented to produce a composite with varying loadings of glass waste nanoparticles (GWNP) in 5, 10, and 15 wt.% with recycled polyethylene terephthalate drinking water bottle waste (RPET). This strategy was based on glass and drinking water bottle waste. An analysis was conducted to evaluate the performance of the composite as filaments for 3D printer applications. This study evaluated the effect of GWNP addition on the chemical structure, thermal and mechanical characteristics of the composite. The Fourier Transform Infrared (FTIR) spectra of the filament composites and RPET composites exhibited similarities. However, the mechanical strength and thermal stability of the filament composites were enhanced due to the increased GWNP content. Furthermore, the results indicated that the filament developed could be utilized for 3D printing, as demonstrated by the successful fabrication of the filament composite, including 5 wt.% GWNP, using a 3D printer pen. The production of filaments using GWNP and RPET matrix presents a cost-effective, high-yield, and ecologically beneficial alternative. The present study may pave the way for the future advancement and utilization of 3D printing filaments by treating hazardous waste and using more ecologically friendly materials in design applications.