Online learning options for high school students have been growing over the last decade, and yet there is little research around what student characteristics increase their likelihood of success. One characteristic that studies have reported mixed results in face-to-face learning environments is Dweck's mindset theory. This hierarchical multiple regression study attempts to answer the question: What is the relationship between mindset and academic performance among online high school students? Participants of this study included 79 high school students from eight virtual schools. The students' mindset score was determined using the "Revised Implicit Theories of Intelligence (Self-Theory) Scale." The primary measure of student performance was their grades in the online classes in which they were enrolled, and the control variables in this study were gender, class size, and class type. The results of this study determined that there was no significant relationship between a student's mindset and their academic performance in an online class. This study hoped to help fill the gap in the research around online learning and mindset. Although there were no significant findings related to the research question, future researchers could make minor adjustments to this study and identify factors that could positively influence online learners. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]