Objectives The purpose of this study is to design a 10-hour STEAM program with the subject of data and to develop a blended learning-based high school STEAM program through the application of a pilot school. Specifically, in order to improve learners' data literacy, we develop a topic discussion STEAM program using data so that learners can directly select discussion topics, find data as a basis to support their thoughts, and critically analyze other learners' claims. Methods To this end, a study was conducted to develop and apply a topic discussion program based on data that can be actually applied on a blended learning basis according to the ADDIE model, a general model of program development. Specifically, in the analysis stage, literature research on data literacy and topic discussion was conducted, and the topic discussion STEAM program using data was selected as the main learning element. In the design stage, the entire subsequent schedule of the blended learning-based STEAM program was designed and student activity sheets were produced. In the development stage, the instruction plan for each class and the student study paper were embodied, and the first revision was made through the first expert review. The implementation stage was conducted from September to December 2021, and nine teachers applied the revised STEAM program to 717 students in the first and second grades of high school. In the evaluation stage, The results of the program application were analyzed, and the final STEAM program was prepared through the second expert review process. Results In order to help students improve data literacy, five stages of discussion using data were developed based on the STEAM framework. In consideration of the pandemic situation, step-by-step activity papers and evaluation papers for online and offline classes were developed, respectively, and it was confirmed that they had a positive effect on learners' communication capabilities, discussion capabilities, collaboration, and problem-solving skills. Conclusions Through the results of this study, the topic discussion STEAM program using data will be able to improve the data literacy of learners who will live in a future society where big data is commonplace. In addition, the STEAM program designed based on blended learning is expected to be available in various learning environments in the future.