This research aims to enhance mathematical proficiency and stimulate creative thinking among 10th-grade students through the implementation of the 5E Inquiry-Based Learning approach with Supplementary Media. The study explores the effectiveness of this pedagogical approach in transforming the learning experience and outcomes in mathematics education. The study focused on comparing students' performance before and after the intervention, as well as investigating their creative thinking abilities in terms of flexibility, originality, fluency, and elaboration. The participants consisted of 10th-grade students from a large-sized school in the northeastern region of Thailand, specifically one classroom comprising 40 students. The tools include Lesson plans, Mathematics Proficiency test and Creative thinking skills test. The results revealed a significant improvement in mathematical proficiency following the implementation of the 5E Inquiry-Based Learning Approach with supplementary media, with a notable increase of 37.25%. Prior to the intervention, students scored an average of 4.64 out of 20, which increased to 12.08 out of 20 post-intervention. Furthermore, the investigation into creative thinking skills indicated that students exhibited a proficient level overall, with an average score of 22.60 out of a maximum of 32 points. The analysis of specific dimensions of creative thinking revealed average scores of 5.60 for Originality, 5.78 for Fluency, 5.63 for Flexibility, and 5.60 for Elaboration.