Leachate treatment represents a key problem related to landfill operations, a liquid waste generated from a mixture of rainwater infiltration, waste decomposition, and surface runoff. Mercury is among the hazardous contaminants commonly found in landfill leachate. The use of electrocoagulation has shown potential in eliminating mercury from this leachate. This study aimed to investigate the impact of varying electric voltages (4 V, 8 V, and 12 V), contact times (15, 30, 45, and 60 minutes), and electrode spacing (1 cm and 2 cm) on the efficiency of mercury removal during a 60-minute electrocoagulation process. It was found that the most effective mercury removal, with an efficiency of 99.32%, occurred at 12 V with a 60-minute treatment duration and a 1 cm gap between electrodes. An ANOVA analysis revealed that 86.1% of the influence of the investigated variables on mercury reduction was statistically significant. Furthermore, data from the electrocoagulation process were utilized to examine the effects of operational parameters, evaluated to determine the most appropriate adsorption kinetics and isotherm models. The pseudo-second-order kinetic model and the Freundlich isotherm exhibited the highest correlation with the experimental findings. Among the models evaluated, the kinetic model presented the strongest correlation with the experimental results, as evidenced by a high correlation coefficient (R² = 0.9895).