Because of their longevity, bricks have been used to construct many constructions over many hundreds of years. The brick industry in India consumes about 24 million tonnes of coal annually, making up approximately 8% of the country’s total coal usage. Burning of bricks in kilns release green house leading to air pollution. The primary goal of this study is to explore the creation of interlocking Geopolymer lightweight bricks by utilizing industrial waste such as Ground Granulated Blast furnace Slag (GGBS). The aim is to mitigate the environmental issues associated with traditional bricks. Also an effort has been made to use treated expanded clay as the fine aggregates to reduce the weight of the brick. The primary factors such as binder aggregare ratio and the molarity of NaOH are varied in this investigation. In the first phase aggregate binder ratio is varied keeping the molarity of sodium hydroxide solution as 12 M. During the second phase, the molarity of NaOH was changed at different levels: 8, 10, 12, 13, and 14, using the optimized mix determined in the first phase. The evaluation of the brick’s performance was carried out in two stages, focusing on Dimensions Tolerance, Compressive Strength, Water Absorption, and Efflorescence, following the guidelines of IS 1077, IS 3495, and IS 12894. The findings demonstrate that Geopolymer bricks exhibit favorable properties, opening up promising opportunities for producing Geopolymer interlocking bricks using industrial waste. This study contributes to environmental relief by promoting the synthesis of sustainable building materials, alleviating strain on the environment.