One-thousand-one-hundred-and-ninety-one school counselors completed an online survey regarding advocacy for and with gender minority students comprising transgender and intersex students (school counselor gender minority advocacy competence). School counselors completed a battery of three competency-based assessments to assess their levels of gender identity counselor competence, intersex counselor competence, and school counselor gender minority advocacy competence. They also completed a demographic form so that competency levels could be examined with demographic variables. Attitudes, school level placement, gender, sexual orientation, gender identity counselor competence, and intersex counselor competence were significantly related to advocacy for and with gender minority students. These findings have implications for the application of identity behavior theory to examine the experiences and behaviors of minoritized individuals and those who advocate for them. These advocates include school counselors and other helping professionals who work with gender minority students.