The examination of belonging in schools, connecting school belonging to a plethora of academic and psychosocial outcomes, has been well established in the literature. Researchers have measured school belonging most frequently with the Psychological Sense of School Membership, but its psychometric properties have been called into question by several researchers. Further, the scale measures 1 subset of belonging (i.e., school), leaving out powerful belonging connections in other areas of a student's life, namely peers and family. The current study examines the development and validation of the Milwaukee Youth Belongingness Scale. This process was examined by utilizing item response theory and a secondary analysis confirming the factor structure and the validation of the scale by comparing it to other constructs. The results confirm a 9-item scale that involves a total scale score and 3 factors (School, Peers, Family). Implications for mental health professionals and future research are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).