- Multiple Sclerosis (MS) is an autoimmune condition that affects the central nervous system, and impacts the lives of over 400,000 individuals in the US. These individuals face unpredictable relapses of disabling conditions, are less active and experience poorer quality of life than the general population. Health professionals are challenged to find ways to increase engagement in health promoting behaviors that can improve function and overall wellness for this population. The major objective of this dissertation was to expand the literature on promoting health behaviors and wellness through self-compassion for individuals with MS. One theoretical model that has the potential to help researchers and program developers understand how to effectively improve engagement in health behaviors for individuals with MS is Reyes’ model of self-compassion. The first aim of the first study was to cross-validate Reyes conceptual model of self-compassion among individuals with MS. Although the model is promising, recent studies suggest fatigue may play a unique role for individuals with MS. The second aim of the first study was to examine the utility of an alternative model, which expands upon Reyes’ model. Furthermore, self-compassion has been shown to improve resilience and quality of life in the general population. The second study aimed to understand the relationship between self-compassion, resilience and health-related quality of life for individuals with MS. Individuals (N = 259) participated in a survey measuring their perceived fatigue, self-compassion, psychological needs related to exercise, resilience, health-related quality of life, and self-reported physical activity, as well as a demographic questionnaire. Participants were predominately white (90%) females (84%), with a relapse-remitting MS course (73%), and a mean age of 48.60 (SD = 10.46). Study 1 validated the use of Reyes’ conceptual model of self-compassion. However, the alternative model, which added direct paths to psychological needs and fatigue, showed improved fit over Reyes’ model for this population. Results demonstrated that fatigue predicted engagement in physical activity in both models, which was expected. However, in the alternative model, fatigue significantly negatively predicted psychological needs for engaging in exercise, but showed a non-significant, weak relationship with physical activity behavior, which was unexpected. Study 2 examined the relationship between self-compassion, resilience, and health-related quality of life for individuals with MS using mediation analysis. Results from this study showed that resilience was a partial mediator between self-compassion and health-related quality of life. The results from these studies can inform future health interventions seeking to improve health-related quality of life and engagement in physical activity in this population. Both of these studies contribute to the theoretical knowledge of self-compassion, wellness, and behavior change for individuals with MS.