The present study evaluated the effect of convective drying on the physicochemical, functional, and microstructural properties of the powders of leaves of Agave angustifolia Haw (agave espadin) and Agave rhodacantha Trel (agave mexicano) at temperatures of 70, 90, and 110 °C. The leaves correspond to the agro-industrial waste generated by the mezcal industry. The results indicate that convective drying at a temperature of 110 °C induces the greatest microstructural modification of the powders and improves their functional properties compared to thermal treatments at 70 and 90 °C. The obtained powders in the present investigation show important contents of dietary fiber in a range of 45.53 ± 0.07 to 55.31 ± 1.60 g/100 g. According to the results of physicochemical analysis, the obtained powders show high storage stability, pointing out that the employment of convective drying in the processing of agave leaves at high temperatures is an emerging tool for the obtention of waste-derived powders with high impact in the development of future functional foods, while contributing to the mitigation of the environmental impact of the mezcal industry.