Cement is a crucial component in mortar because of its strong binding properties. The demand for cement increase periodically due to the growth of buildings and infrastructure. However, the production of cement requires a significant amount of energy and is a significant contributor to global warming. It is environmentally unfriendly material. To overcome the drawbacks of cement, researchers have started conducting studies using agricultural and industrial by-products to partially replace cement, and providing sustainable construction materials. This research investigated the potential use of marble and glass waste powder as a supplementary cementitious material in mortar production. Cement was partially replaced with varying percentages (0%, 5%, 10%, 15%, 20%, 25%, and 30%) of marble and glass waste powder by weight. The mortar mix design was conducted according to ASTM C109. Samples of mortar cubes with size (50 x 50 x 50) mm were properly prepared and cast for curing periods of 3, 7, 28, 56, and 91 days. This study examined physical tests of cement and sand, X-ray fluorescence (XRF), BET surface area of marble and glass waste powder, workability, mechanical or hardened properties (compressive strength, density, ultrasonic pulse velocity (UPV)), durability (sulfate attack, water absorption, and porosity), Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), Differential thermal analysis (DTA), and Fourier transform infrared (FT-IR) properties on mortar. The BET result indicates that marble and glass waste powders are finer than cement. According to ASTM C618, XRF results show that glass waste is siliceous, while marble waste powder is calcareous material. The compressive strength of mortar at 10% MGWP increased by 25.6% at 28 days and 17.26% at 56 days. The microstructure and durability properties were improved due to compacted morphology resulting from secondary C-S-H formation of MGWP and filling effects compared to control mixes. Additionally, the mechanical and durability properties are improved up to 15% MGWP replacement compared to control mixes. Thus, using marble and glass waste powder for mortar production gives better result up to 10% MGWP replacement. Keywords: Marble waste powder, Glass waste powder, Mechanical performance, Microstructure, Durability