Reflecting the recent consensus that challenges in personality functioning often onsets in adolescence, and the move toward dimensional models of personality pathology such as the level of personality functioning (LPF) of the alternative model for personality disorders, it is important to have validated measures that can assess LPF in young people. The Level of Personality Functioning Scale-Brief Form 2.0 (LPFS-BF 2.0) is the briefest measure of LPF and may be particularly well suited for assessing LPF in youth; however, it has yet to be formally validated in youth. Therefore, the current investigation evaluated the psychometric properties of the LPFS-BF 2.0 in adolescents drawn from a community sample of ethnically diverse North American youth (N = 194, age 12-18; 58% female). Factor structure, gender invariance, reliability, convergent validity, incremental validity, and criterion validity were evaluated. Results demonstrated support for the LPFS-BF 2.0's unidimensional factor structure, as well as high internal consistency. Configural, metric, and scalar measurement invariance was supported across male and female genders, as well as convergent validity. Relative to the Personality Inventory for the DSM-5 Brief Form and Levels of Personality Functioning Questionnaire 12-18, the LPFS-BF 2.0 demonstrated additional variance in predicting borderline personality features, and internalizing and externalizing problems. Study findings support the English version of the LPFS-BF 2.0 as a brief and psychometrically sound instrument for assessing LPF in youth and adolescents.