There are two purposes of this study. 1) Describe the developing process of mathematics learning process by using flipped classroom integrated by five disciplines, namely science, technology, engineering, art, and mathematics (STEAM). 2) Test the effectiveness of mathematics learning with flipped classroom-oriented STEAM in high school. Methodology: This research is research and development (R&D) with the ADDIE model, which comprises five stages, i.e. analysis, design, development, implementation, and evaluation. Data collection techniques were done by observation, walkthrough, and tests. The research was conducted in SMA Negeri 1 Gemolong on 2019/2020 academic year. Data collection techniques were done by observation, walkthrough, and tests. Results: The results showed that 1) The process of learning mathematics with flipped classroom-oriented STEAM, namely (a) Before face-to-face stage in class, students were asked to learn independently by watching learning videos on the internet; (b) Students were divided into several heterogeneous groups and given problems and projects in each group (groups of 4-6 students); (c) Each group was asked to solve a problem by integrating five disciplines (STEAM); (d) The teacher facilitated and monitored students in designing the project; (e) Students completed projects outside the classroom; (f) Students presented project results in class; and (g) In the end of a lesson, students were given a quiz or a short test. 2) Mathematics learning through flipped classroom-oriented STEAM was effective in terms of material mastery. Applications/Originality/Value: The findings of this research give overviews regarding to the implementation of flipped classroom integrated by STEAM learning which increases students' understanding.