Science education should help unleash the creative potential of students, for which an instrument to accurately assess creativity is required. This study aims to develop and validate such a scale to assess science classroom creativity (SCC), which is the creativity expressed by students in the process of learning either individually or collectively in a science classroom. This study is carried out in the following four stages to achieve this goal: (1) item generation, (2) scale development, (3) scale validation, and (4) scale application. The results of this study indicate that the developed SCC scale with 49 items is a valid and reliable instrument that consists of nine components: cognitive/affective student characteristics, internal/external engagement in science class, science classroom environment, cognitive/emotional support of the science teacher, and individual/collective creative behaviour. Furthermore, the application of the scale provides science teachers with opportunities to: understand creativity more deeply, think reflectively about their teaching practice, and produce differentiated instructional designs to promote creativity.