As higher education changes to reach larger numbers of students via online modalities, both at the undergraduate and graduate levels, the issue of student attrition and other measures of student success become increasingly important. While research has focused largely on undergraduate online students, less has been done in the area of online non-traditional doctoral student success, particularly from the student trait perspective. On the trait level, the concept of grit has been identified as an important element of the successful attainment of long-term goals. Earning a doctorate can be classified as a long-term goal; therefore the purpose of this study was to examine the influence of doctoral student grit scores on student success. Success was measured in three ways: (a) in terms of persistence as measured by longevity in the program (the number of courses a student had successfully completed), (b) by examining current student GPA, and (c) by studying whether or not students have reached the critical milestone of successfully defending their dissertation proposal. The results of the study found no significant differences in mean grit scores for first, second, or third year students, nor found differences in mean grit scores for students that had or had not successfully defended their dissertation proposals. However, significant relationships were found between grit and current student GPA, grit and the average number of hours students spent of their program of study weekly, and grit and age. The results of this research are important for informing how doctoral education is structured, which characteristics may help students succeed, as well as providing areas for future research. [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/en-US/products/dissertations/individuals.shtml.]