Scholars and activists of color have urged White allies to engage in racial justice work led by the voices of Black, Indigenous, and People of Color (BIPOC). However, to date, most research on racial allyship has centered exclusively on the perspective of White allies themselves. To address this gap in the literature, Chapter 1 utilized constructivist grounded theory methodology to expound on the characteristics of racial allies as described by BIPOC. Chapter 2 utilized the qualitative themes that emerged from Chapter 1 to develop the 27-item Racial Allyship Characteristics Scale (RACS) across two studies. In Study 1, exploratory factor analysis with 275 White college students identified the six dimensions of allyship described by BIPOC participants in Chapter 1 were subsumed into three factors: Antiracist Action and Skills (13 items), Critical Awareness (8 items), and Relationship Building (6 items). In Study 2, the three-factor model was confirmed with an additional sample of 305 White college students. The RACS demonstrated temporal stability over a two-week period. Additional validity was supported through positive associations with antiracist behaviors, awareness of racism, and inverse associations with color-evasive racial attitudes. The potential utility of the RACS and future directions for ongoing development are discussed.