As the research on familism values, or cultural values relating to support, interconnectedness, and obligations has blossomed, scholars are increasingly interested in the applicability and impact of familism values across diverse racial/ethnic youth. However, existing measures of familism tend to be long, posing potential practicality issues and have not been validated for use across youth from different racial/ethnic groups. Through a series of conceptual steps and exploratory and confirmatory factor analyses, we developed the Short Attitudinal Familism Scale, a 6-item, shortened, unidimensional version of Lugo Steidel and Contreras's (2003) 18-item Attitudinal Familism Scale. This measure was created and validated in a sample of 671 Black, Latinx American, Asian American, and Multiracial youth (M age = 17.23, 73.6% female). Multigroup measurement invariance testing indicated that the Short Attitudinal Familism Scale was almost wholly noninvariant and may be used reliably across racial/ethnic groups. Finally, we established construct validity by demonstrating negative associations with depressive symptoms in all but Asian American youth and positive associations between familism and ethnic-racial identity (ERI) for all youth. In conducting these tests using regressions using observed mean scores and structural equation modeling (SEM) using latent variables, we demonstrated that using a mean score of this scale led to small and negligible amounts of attenuation in estimates and similar statistical conclusions compared to those derived from SEM. Our study adds to the field by introducing a practical, unidimensional measure of familism values that may be used across racial/ethnic groups.