This study aimed at exploring the effect of Edmodo use on developing Saudi English as a Foreign Language (EFL) students' Self-Directed Learning (SDL). It employed a quasi-experimental design that included a one group design. The participants (n = 45) were all fifth level students at Languages and Translation Department, Arar Faculty of Education and Arts, Northern Border University, Kingdom of Saudi Arabia. They were pre-tested before the treatment by using the pre Personal Responsibility Orientation to Self-Direction in Learning Scale (PRO-SDLS). They were post-tested after the treatment by using the post PRO-SDLS. The researcher taught the participants during the treatment which based on allowing them to use Edmodo in carrying out a project. The results revealed that a statistically significant difference in the participants' SDL between the pre PRO-SDLS and the post PRO-SDLS in favor of the post PRO-SDLS. Hence, it can be concluded that Edmodo helped the participants develop their SDL on the post PRO-SDLS. Some recommendations and suggestions for further research were included.