Bemisia tabaci MEAM1 is a globally devastating agricultural pest that severely affects soybeans. This insect causes damage by sucking sap, injecting toxins, and excreting honeydew, which promotes the growth of phytopathogenic fungi. Chemical control has proven ineffective and harmful, making the search for resistant cultivars essential. This study aimed to categorize the resistance mechanisms of soybean cultivars to B. tabaci MEAM1 damage through antibiosis testing and to evaluate changes in photosynthetic rates and antioxidant enzyme activity in infested and non-infested plants. The cultivars used were OLIMPO, LATITUDE, M8808 (resistant), and BÔNUS (susceptible). An antibiosis test with daily analyses until the emergence of all insects was conducted. The design was completely randomized with four treatments and six repetitions. The number of eggs, nymphs, and adults per leaflet, as well as unviable eggs and nymphs, egg-nymph, and egg-adult development, were evaluated. Four plants of each cultivar were analyzed for physiological variables under B. tabaci MEAM1 stress and compared with non-infested plants. Gas exchange measurements included photosynthetic rate, leaf transpiration, stomatal conductance, and internal CO2 concentration, with calculations for water use efficiency and carboxylation efficiency. Plants infested for 25 days were evaluated for antioxidant enzyme activity and hydrogen peroxide content. Results showed that the Bônus and Latitude cultivars are susceptible to infestation but respond with biochemical defense mechanisms. Olimpo and Latitude exhibited photosynthetic changes under infestation. The M8808 cultivar exhibited higher concentrations of hydrogen peroxide, indicating that its resistance is linked to both constitutive defense mechanisms and the signaling function of hydrogen peroxide.