This article presents the development of the Antiracist School Counseling Inventory (ASCI), an instrument designed to support school counselors engaging in antiracist counseling practice. We administered the ASCI to a sample of 457 practicing school counselors. Results of an exploratory factor analysis yielded a 19-item exploratory model encompassing four factors: (a) Awareness of Institutional and Educational Racism, (b) Promoting Inclusion and Equity, (c) Challenging Racism, and (d) Responsive Leadership and Advocacy. The ASCI demonstrated promising evidence of convergent validity and internal consistency reliability. We discuss the development of the ASCI and implications for school counselors and future research.