Although the International Baccalaureate Organization (IBO) recognizes the importance of school counselors, there is limited guidance about the expectations and roles of school counselors in serving the diverse needs of students in IB schools. With the IBO's movement toward a mission of "IB for All" to address equitable access to academic rigor, this also aligns with school counselors' ethical responsibilities as advocates, collaborators, and leaders to promote access and equity for all students. The authors (a) highlight the work of one school counseling program that developed and implemented initiatives, using the U.S.- based ASCA National Model (ASCA, 2019a) as a framework, to increase access to the IB program for diverse students and families; and (b) articulate the potential roles of school counselors in promoting students' academic, social and emotional, and postsecondary development and trajectories from grades nine through 12 in the IB Middle Years and Diploma Programs.