Loneliness is an adverse phenomenon that tends to peak during adolescence. As loneliness is a subjective state, it is different from the objective state of being alone. People’s attitudes toward being alone can be more or less negative or positive. Cultures differ in the form and meaning of social behavior, interpersonal relationships, and time spent alone. However, for cross-cultural comparisons to be meaningful, measurement invariance of the measure should be established. The present study examined measurement invariance of the Loneliness and Aloneness Scale for Children and Adolescents (LACA) in a sample of 218 Belgian and 190 Chinese early adolescents, aged 11–15 years. Using nested multigroup confirmatory factor analyses, measurement invariance of the LACA across Belgium and China was established. More specifically, evidence was found for configural, metric, and partial scalar invariance. Because partial scalar invariance was established, the two cultural groups could be compared. No significant differences were found for peer-related loneliness. Regarding the attitudes toward aloneness, Belgian adolescents were more negative and less positive toward being alone than Chinese adolescents. The present study is encouraging for researchers who want to use the LACA for cross-cultural comparisons, in that we found evidence for measurement invariance across two disparate cultural groups speaking completely different languages.