BACKGROUND: Children ages 6 to 17 years can accurately assess their own food insecurity, whereas parents are inaccurate reporters of their children's experiences of food insecurity. No globally applicable scale to assess the food insecurity of children has been developed and validated. OBJECTIVES: We aimed to develop a globally applicable, experience-based measure of child and adolescent food insecurity and establish the validity and cross-contextual equivalence of the measure. METHODS: The 10-item Child Food Insecurity Experiences Scale (CFIES) was based on items previously validated from questionnaires from the United States, Venezuela, and Lebanon. Cognitive interviews were conducted to check understanding of the items. The questionnaire then was administered in 15 surveys in 13 countries. Other items in each survey that assessed the household socioeconomic status, household food security, or child psychological functioning were selected as criterion variables to compare to the scores from the CFIES. To investigate accuracy (i.e., criterion validity), linear regression estimated the associations of the CFIES scores with the criterion variables. To investigate the cross-contextual equivalence (i.e., measurement invariance), the alignment method was used based on classical measurement theory. RESULTS: Across the 15 surveys, the mean scale scores for the CFIES ranged from 1.65 to 5.86 (possible range of 0 to 20) and the Cronbach alpha ranged from 0.88 to 0.94. The variance explained by a 1-factor model ranged from 0.92 to 0.99. Accuracy was demonstrated by expected associations with criterion variables. The percentages of equivalent thresholds and loadings across the 15 surveys were 28.0 and 5.33, respectively, for a total percentage of nonequivalent thresholds and loadings of 16.7, well below the guideline of <25%. That is, 83.3% of thresholds and loadings were equivalent across these surveys. CONCLUSIONS: The CFIES provides a globally applicable, valid, and cross-contextually equivalent measure of the experiences of food insecurity of school-aged children and adolescents, as reported by them.