A national sample of educators were surveyed to identity the attitudes, beliefs, school culture, and perceived barriers that would predict whether educators would intervene to stop bias and harassment directed at lesbian, gay, bisexual, transgendered, and questioning (LGBTQ) youth in schools. The survey questionnaire was organized according to the theory of planned behavior (TpB), a theoretical model linking attitudes to behavior. A sample of 968 teachers, school psychologists, and school counselors participated. Factor analysis indicated that the three TpB components (attitude, subjective norm, and perceived behavioral control) accurately predicted behavioral intention to advocate for LGBTQ youth. Path analysis supported the components of TpB in predicting behavioral intention, accounting for 21% of the variance. The path coefficients linking attitudes and subjective norm to behavioral intention were particularly robust and less so for perceived behavioral control. Implications for intervention and training of school personnel to improve advocacy for LGBTQ youth and reduce bias and harassment are discussed.