Social media offers significant potential to enhance agricultural education programs and address systemic challenges in agriculture, particularly in developing countries such as Iran. If farmers adopt this new technology, it could begin a new era in agricultural extension programs. However, there is currently limited information about the social acceptance of social media as a source of learning and information. To fill this gap, this study investigates farmers’ intentions and behaviors regarding the use of social media for learning and information sharing in Khuzestan Province, southwestern Iran. To achieve this goal, this study employs an Extended Theory of Planned Behavior and incorporates two additional variables—media literacy and self-identity—to assess social media adoption among Iranian farmers. Data were collected from a sample of 371 farmers through a structured questionnaire and analyzed using structural equation modeling. Results demonstrate that adding media literacy and self-identity to the TPB significantly improves its predictive power, explaining 41% of the variance in intentions and 48% in behavior—compared to 29 and 39% in the original TPB model, respectively. Findings highlight the robustness of the extended TPB for examining social media acceptance in agricultural settings, with the added constructs enhancing the model’s explanatory power. The study also discusses practical implications for promoting social media as a tool for agricultural learning and information sharing among farmers and policymakers can leverage these findings to design social media–based extension training programs. Moreover, the results aim to inform decision-makers in developing new initiatives or adapting existing policies to promote the adoption and effective use of social media in agricultural communication. Directions for future research are proposed to further investigate the role of social media in agricultural development.