There is a gap in research regarding examination of the relationship between burnout in special education school support staff members and their perception of locus of control (LOC) in their work environment. The purpose of this concurrent nested mixed methods study is to determine if there is a relationship between burnout and locus of control in professional school support staff (PSSS) working with special education students, by analyzing survey responses of a sample consisting of 86 PSSS in the northeastern United States. This study elicits data for quantitative analysis with Maslach Burnout Inventory and Rotter's Internal-External LOC Scale utilizing Pearson's Correlation and multiple regression analyses. The survey contains a contextual qualitative portion consisting of 10 open-ended question sets for thematic analysis. The findings showed that increased internal locus of control is associated with decreased burnout in the subscales of emotional exhaustion and depersonalization. Notably, findings showed that increased internal LOC is associated with greater burnout in the subscale of reduced personal accomplishment. Recommendations for future research were made to conduct additional quantitative and qualitative research studies that explore the lived experiences of PSSS in special education, as well as to explore the usefulness of Dialectical Behavior Therapy (DBT) and Mindfulness as possible therapeutic approaches to counteract the effects of burnout. [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.]