The purpose of this study is to develop a valid, practical, and effective contextual-based LKPD for grade X students at Tasik Raja Private High School in the 2025/2026 school year. This study used the Research and Development (R&D) method with the ADDIE model, involving 30 students from class X-2. Data was collected through validation sheets of teacher and student response questionnaires, as well as tests (pre-test and post-test). The data collected was analyzed to assess the validity, practicality, and effectiveness of the LKPD. The results showed that the LKPD was very valid, with an average score of 90.34%. In addition, this LKPD is very practical, as evidenced by the response questionnaire of teachers (95%) and students (90.83%). The increase in effectiveness can also be seen from the results of the post-test, where this LKPD succeeded in improving student learning outcomes with a score of 0.7627. Thus, it can be concluded that this LKPD is valid, practical, and effective in improving the learning outcomes of high school class X students.