In this study, the effect of crushed glass waste (GW) as fine aggregate on the mechanical properties of geopolymer concrete was studied. Where the glass was ground and graded to particle sizes less than 4.75 mm and incorporated into the concrete in replacement ratios of 0, 20, 40, 60, 80, and 100% instead of fine aggregate, were designed 12 mixes, 6 mixtures using ambient room treatment and 6 mixtures treated in an oven at 85 degrees for 8 h. compressive strength, tensile strength, and flexural strength tests were conducted, and the results show that when replacing 20%, compressive strength, tensile strength, and flexural strength are better than the control mixture at ages 7, 28, and 56 days. The compressive strength increased from 32.37 MPa to 34.67 MPa at the age of 28 days in heat treatment. The strength decreased when replacing 40% to 33.28 MPa, but also higher than the control mixture, while the tensile strength and flexural strength decreased at this ratio. When 100% of the GW was replaced, the resistance decreased by 28% over the control mixture. Based on the results obtained from this study, it is recommended to use 20% of GW instead of regular sand to reduce landfill waste in nature.