Removal of pharmaceutical contaminants from wastewater has become a critical environmental concern. Adsorption of amoxicillin onto commercially available activated carbon in Sri Lanka is examined in this study. Batch experiments indicated that as the dosage of the adsorbent is increased the percentage removal of amoxicillin is increased. Furthermore, the study investigated the influence of pH on amoxicillin adsorption, revealing consistent high removal percentages (90%) across a pH range of 2 to 10. However, a notable deviation occurred at pH 12, where the removal percentage decreased to 60%. Adsorption Isotherm data were fitted to Langmuir and Freundlich isotherm models. The results showed a correlation coefficient for Langmuir isotherm model is 0.9724. Maximum adsorption capacity and Langmuir constant were calculated as 192.31 mg/g and 0.044 L/mg respectively. Freundlich model constants was determined to be 9.87 (mg/g) and Freundlich exponent that characterizes the adsorption intensity was 1.312. Kinetic analysis revealed adsorption experiment data best fit for pseudo second order model and rate constant for pseudo second order model increases as the activated carbon dosage increases, indicates that higher dosages of activated carbon enhance the adsorption kinetics of amoxicillin. Analysis of kinetic experimental data through the intra-particle diffusion model, shows that the rate-limiting step of the adsorption of amoxicillin onto activated carbon is the intra-particle diffusion phase.