In this study, a behavioral influence model based on cognitive theory was developed to investigate foremen’s influences on construction workers’ safety behavior. In the model, three foreman behaviors were considered, such as leading by example (LE), safety teaching (ST), and safety monitoring (SM). Five cognitive stages of a worker are also considered in the model, such as situation awareness, safety knowledge, subjective norm, safety attitude, and taking action. To obtain empirical data for the model parameters, a survey was conducted on a construction site in Seoul, South Korea, where the foreman–worker behavioral interactions and workers’ unsafe behavior of taking shortcuts were observed. The model was established as Agent-Based Modeling (ABM) using AnyLogic software. Four scenarios of foremen’s behavior were simulated using the model. The result shows that LE behavior has a positive, but weak significant influence on workers’ safety behavior. ST was found to have a positive and the most significant influence on workers’ safety behavior. Moreover, it should be provided with appropriate safety monitoring to maximize its effectiveness. The research findings promote stakeholders’ understanding of the influence of foremen on workers’ safety behavior and lead to the formation of informed policies and future research directions in the study field.