Natural fibres such as Agave Americana leaf fibre are gaining interest as reinforcements in polymer composites due to their low cost, low density, and biodegradability. In this study, hybrid composites reinforced with both glass fibre and Agave Americana leaf fibre were fabricated by varying three process parameters: blend ratio of the two fibres, fibre volume fraction, and areal density of the hybrid reinforcement. The physical, mechanical, and thermal properties of the resulting composites were characterized. A multiobjective optimization was performed using the Taguchi method coupled with grey relational analysis (GRA) and response surface methodology (RSM). GRA helped translate the experimental results to a single grey relational grade, enabling optimization of the multiple responses. Additionally, response surface methodology (RSM) based on a central composite design was used to develop predictive models for the measured responses. The optimal combination of process parameters was identified to simultaneously maximize the tensile strength, flexural strength, and impact strength, and minimize the water absorption of the hybrid composites. The results showed that a blend ratio of 90% glass fibre and 10% Agave fibre, a fibre volume fraction of 59%, and an areal density of 550 gsm provided the most balanced properties. The Taguchi-GRA and RSM techniques were found to be effective tools for optimizing the multiple performance characteristics of the hybrid Glass-Agave composites. This study demonstrates that hybridization with natural fibres can enhance the properties of glass fibre composites while reducing their environmental impact.