The rapid development of science and technology encourages renewal efforts in the utilization of various technological results in the learning process, such as utilizing digital-based learning media. This research aims to produce e-module learning tools based on discovery learning on quadratic function material for class X SMA students that are valid, practical, and effective. The research method used is Research and Development with Thiagarajan 4-D development model: define, design, develop, and disseminate. The subject of this research is the production of e-modules based on the discovery learning model. The object of this research is the students of SMA Negeri 1 Purba, totaling 33 students. The instruments used in this study were validation questionnaires and student responses to the e-modules developed as well as student learning outcomes tests. The results of this study indicate that the e-Module developed has met the requirements of validity and practicality as stated in the results of the questionnaire given. In addition, the e-module developed was also declared effective based on the student learning outcomes test with an average of 78,79% and included in the good category.