School counselors are being called to reestablish their roles as leaders, advocates, collaborators, and change agents. Unfortunately, several barriers hinder school counselors' advocacy, including limited instruction and training on advocacy during preparation programs, lack of knowledge or awareness of resources and policies, limited access to support services for students and families, high counselor-to-student ratios, role confusion, and school culture/leadership. This quantitative research study explores the relationship between counselors' trust in their principals and school counselors' advocacy actions. The study investigates what leadership characteristics--ability, benevolence, or integrity--most significantly relate to counselors' advocacy actions and promote school counselors' efforts to increase advocacy behaviors across each advocacy domain. A correlational research design was conducted in South Carolina, where 66 high school counselors participated in an online survey consisting of a demographic questionnaire, Omnibus Trust Scale, and Advocacy Competencies Self-Assessment Survey. Data analysis using the Pearson Product Moment Correlation test confirmed statistically significant relationships between the variables, indicating a moderate negative relationship between school counselors' trust in their principals and advocacy actions. Analysis of the leadership characteristics and advocacy behaviors revealed that principals' traits of ability and benevolence were more significantly related to counselors' engagement in advocacy actions in the community collaboration and public information domains. The author discusses implications and recommends further research exploring how the principal-school counselor relationship impacts counselors' advocacy actions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]