Abstract: Background: This study aimed to develop an Interactive Teaching Module based on Differentiated Instruction in geometry material to accommodate the diversity of mathematical problem-solving abilities of seventh-grade students at MTs Mujahidin Pontianak. The study employed a Research and Development (R&D) method using the 4D development model modified into 3D, consisting of the define, design, and develop stages. The research subjects consisted of four expert validators, namely two Mathematics Education lecturers, one Information Technology Education lecturer, one mathematics teacher, and 30 seventh-grade students as the trial subjects. Data were collected through validation sheets, teacher and student response questionnaires, and tests of mathematical problem-solving abilities. The results showed that the module met the criteria of being highly valid with an average validation score of 94.7%, highly practical based on teacher responses of 93.33% and student responses of 85.58%, and effective with an average posttest score of 71.67 and a learning mastery percentage of 66.67%. The module also improved students’ activeness, enthusiasm, and ability to solve problems using Polya’s problem-solving stages according to their respective abilities. Therefore, the module is feasible to be used in mathematics learning to support the diversity of students’ abilities.