The bauxite beneficiation process in the Amazon generates a significant amount of tailings, which were historically stored in large basins without a designated purpose. One of these materials is clay obtained from the bauxite washing process, which is rich in Al2O3 minerals, primarily gibbsite and kaolinite, and currently lacks practical applications. This study aimed to explore an application of this tailing in the production of low-temperature geopolymers, considering its material characteristics and availability. Geopolymer synthesis was conducted following a Doehlert-type experimental design to evaluate the properties of the raw materials. The tailing was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray fluorescence (XRF), and inductively coupled plasma optical emission spectroscopy (ICP-OES), whereas the geopolymers were characterized by XRD, FTIR, and mechanical compressive strength testing. The mineralogical composition of the bauxite tailings consists of 45% of low-ordered kaolinite, 34% of gibbsite, and 21% of other minerals. Compressive strength values of the geopolymer produced ranged from 8.99 to 41.89 MPa, a good value for the type of geopolymer produced. The best compressive strength results were obtained at a low Na/Al ratio (0.5–0.6) and low curing temperature, which favors the application of the material for the synthesis of geopolymer, contributing to lower energy consumption and lower CO2 emissions compared with usual geopolymers.