Few assessment tools have been designed to assess motor creativity, and the existing tools have limitations. To bridge this gap, the current study aimed at designing a new movement creativity assessment tool that considers the unique features underlying the expression of creativity through movement. A modified Delphi technique was used to collect experts' perspective and derive tasks suitable for evaluation of the main features underlying movement creativity. From these expert consultations, 11 tasks measuring up to 6 movement creativity variables (i.e., fluency, originality, imagination, elaboration, appropriateness, flow) were included in the initial PLAY Creativity measurement model. The COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN checklist) were followed to ensure methodological quality. Overall, 367 children from grade 4 to 6 participated in this study. Results indicated strong test-retest, inter, and intra observer reliability. Confirmatory factor analysis revealed an inadequate fit of the hypothesized model leading to some modifications. After combining originality and imagination, and excluding elaboration, the final measurement model provided an adequate fit. PLAY creativity, in its final form, has adequate validity and can be considered a reliable instrument to assess movement creativity in children. This study thus provides a useful tool to assess and promote movement creativity.