This paper examined the psychometric properties of the French version of the Children’s Chronotype Questionnaire (CCTQ) attending two elementary schools in Luxembourg (n = 172; ages 4–11 years, M = 8.0, SD = 2.1) of either Portuguese (n = 11), Luxembourgian (n = 147), or other (n = 15) ethnicity. Parents completed the CCTQ, from which we used two chronotype scales (i.e. midsleep point on free days; MSF, multi-item morningness/eveningness; M/E). Results indicated satisfactory internal consistency for M/E scale (α = .70), with high intercorrelation scores (r = .91 between items; r = .87 between scales). As hypothesized, the chronotype of morning and evening type children were different (p= .017, η2 = .06), with the former having an earlier MSF (M = 5:29 h) compared with the latter (M = 5:48 h). The evening group showing the poorest outcomes for the qualitative grades (2014/2015: F(7.308) = 2.34, p = .002; 2015/2016: F(7.996) = 2.46, p = .001). No significant differences in MSFc were found between natives and immigrants. The results indicate that the French version of the CCTQ has adequate reliability and validity for research studies. Evaluating chronotype and sleep behaviors in preschool and school-age children is important, as both may have a negative impact on academic performance.