Science, technology, engineering, and mathematics (STEM) education is regarded by many countries as fundamental to economic growth and as a result received continued attention. Scientist-teacher-student partnership (STSP) is one of the ways to make STEM education attractive and meaningful. However, research on the performance quality of STSP is scarce. Thus, this grounded model research aims to construct a model of performance quality STSP for STEM education. The research employed a sequential exploratory mixed method design which was carried out in two phases. In the first phase, data were collected through semi-structured interviews with 125 students, nine teachers, and ten scientists. Using the constant comparative data analysis technique, the grounded model of STSP emerged from the data which consisted of four main themes: collaboration factors, internal factors, institutional factors, and external factors. In the second phase, a quantitative survey was conducted with 267 science teachers to validate the grounded model of STSP. The data were analyzed using the structural equation modeling method with SmartPLS. The findings of the second phase study confirmed that the grounded model of STSP developed from the first phase can be applied to the wider sample of STEM teachers to enhance the performance quality of STSP in STEM education.