<![CDATA[Sustainability competence is increasingly essential in teacher education, yet existing assessment frameworks insufficiently explain how culturally and religiously grounded ethical values can orient sustainability-related judgment and action. This study addressed this gap by developing and initially validating the Sustainability Competence Instrument Based on Islamic Spirituality for Prospective Teachers in Indonesia (SCIISPTI), integrating established sustainability competence frameworks with Islamic spiritual-ethical principles. Following expert review involving 11 specialists, 49 items across seven conceptual domains were administered to 558 Indonesian prospective teachers. Exploratory Factor Analysis using Varimax rotation retained 40 items organized into four empirical dimensions, with strong sampling adequacy (KMO = 0.959; Bartlett’s χ²(780) = 9000.703, p < .001) and 73.838% explained variance. Internal consistency was high across dimensions (α = 0.906–0.974; overall α = 0.980). The four dimensions reflect the instrument’s empirical organization, while the seven domains preserve its theoretically interpreted competence content. SCIISPTI provides promising initial psychometric evidence for culturally responsive sustainability competence assessment and offers an interdisciplinary approach connecting teacher education, sustainability, psychometrics, and Islamic ethics. More broadly, this study demonstrates how internationally recognized competence frameworks can be contextually grounded without abandoning systematic psychometric evaluation.]]>
