The aim of this study is to design and validate a tool to measure the three levels (knowledge, skill and attitude) of climate change competence in children aged 10–12 years (pre-teens). The scale was designed on the basis of an exhaustive literature review and the evaluation of a panel of CC experts. The initial model constructed was refined based on a pilot study with 67 children and a new evaluation by the panel of experts. The resulting scale was then validated using the confirmatory composite analysis using partial least squares-structural equation modelling (N = 459). The final scale consists of 30 items divided into the three dimensions of competence and the distribution of items is as follows: 14 in knowledge (three items in biophysical processes, three in causes, three in consequences and three in mitigation), nine in skill (three in consumerism, three in transport and three in energy saving) and nine in attitude (three in worry, three in hope and three in interest). Based on the high loadings obtained in the different sub-dimensions in the validation process, it is determined that the instrument “climate change competence scale in pre-teens” is reliable and suitable for the assessment of competence in students of this age range. •The title of the paper has been modified by revising the language.•First title: Validation of the three-dimensional climate change competence scale in preteens.•Second title: Evaluating Climate Change Competence in Preteens: Instrument Development and Validation.