The primary aim of this study was to validate the researcher-developed Teacher Curriculum Ownership Questionnaire (Rahaie et al., 2025) in public elementary schools in Shahreza County. This descriptive-survey research employed a quantitative approach to investigate the impact of various factors on curriculum planning among elementary teachers in Shahreza. The statistical population consisted of 501 elementary school teachers, from which a sample of 217 participants was selected through multi-stage cluster random sampling. The main data collection instrument was a researcher-developed questionnaire comprising 30 items across six subscales. The reliability and validity of the instrument were confirmed using Cronbach’s alpha (0/857) and confirmatory factor analysis (CFA). Data were analyzed using SPSS and RStudio software. The results indicated that the conceptual structure of the instrument demonstrated good coherence, and the indices of convergent validity, discriminant validity, and reliability were at acceptable levels. These findings suggest that the instrument possesses the necessary qualifications to measure the intended components and can be utilized as a reliable and valid tool in future research. The Teacher Curriculum Ownership Questionnaire is a suitable and robust tool for research within educational contexts.