Familial protective factors are an integral part of prevention approaches aimed at problematic behaviour in adolescents. However, there is scarce evidence on the role of familial protective factors in families deviating from the two-parent family configuration. For evaluating targeted (preventive) interventions, a reliable and valid measurement of familial protective factors is crucial. We investigated the factor structure of the Communities That Care (CTC) Family Attachment Scale and tested its measurement invariance in different family structures. Adolescents (n = 2.459, grades 6–11) from Lower Saxony, Germany filled in the German version of the CTC Youth Survey. Our analyses focused on the CTC Family Attachment Scale measuring the adolescent’s attachment to the mother and the father with six items. We evaluated the postulated unidimensional structure of the scale by confirmatory factor analysis (CFA) and tested the measurement invariance using multigroup factor analyses across different family structures (two-parent family/single-parent family). We used SPSS V.23 and the R packages lavaan and semTools. The two-factor solution for the CTC Family Attachment Scale with one factor representing attachment to the mother and one indicating attachment to the father had an adequate model fit in the total sample (χ2(5) = 29.938; p < .001; CFI = .996; TLI = .988; RMSEA = .050, SRMR = .019). This two-factor solution of the CTC Family Attachment Scale showed strong measurement invariance regarding adolescents living in a two-parent family vs. those living with a single parent. The two-factor CTC Family Attachment Scale appears to be a suitable measure to assess family attachment in both two-parent and single-parent families with German adolescents.