This Study aim to investigate the effects of integrated inquiry-based and STEM education learning management on Thai grade 8 students' analytical thinking and learning achievement. The research employed a one-group experimental design with 37 grade 8 students from a public school in Khon Kaen Province, Thailand, selected through purposive sampling. The instruments used in this study included an inquiry-based STEM education integrated learning management plan, a learning achievement test on motion and force, and an analytical thinking test. Data were collected through pretests and posttests on learning achievement and analytical thinking, and ongoing assessments during the learning activities. The data were analyzed using percentage, mean score, standard deviation, effectiveness index (E1/E2), and a paired samples t-test. The results indicated that the overall effectiveness of the learning management, calculated as the E1/E2 ratio, was 77.20/77.57, meeting the predetermined criteria of 75/75. Furthermore, significant increases in analytical thinking and learning achievement were observed at the statistical level of 0.5. These findings support the effectiveness of integrating inquiry-based learning with STEM education in enhancing students' analytical thinking and learning achievement, contributing valuable insights to educational practices in science education.