Gratitude practice has gained attention as a beneficial psychological intervention, with research supporting its positive effects on physical and mental health and well-being. This dissertation presents two manuscripts examining gratitude within chronic illness populations. The first manuscript is a narrative review of gratitude interventions that have been tested in chronic illness populations, including cancer, chronic pain, diabetes, heart disease, HIV, inflammatory bowel disease, neuromuscular disease, and traumatic brain injury. Results indicate that gratitude interventions show the most consistent benefits for psychological outcomes, with chronic pain and cancer populations demonstrating the strongest evidence of effectiveness. Cross-cutting findings suggest that intervention length, dosage, and format meaningfully moderate outcomes, and that further research is needed to better understand for whom and under what conditions gratitude interventions are most beneficial. The second manuscript presents a qualitative study using Interpretative Phenomenological Analysis to explore the experience of gratitude for ten cisgender women living with moderate-severe rheumatoid arthritis (RA). Three superordinate themes were identified: Loss and Disruption, Coping as Continuous Labor, and Gratitude as Practice, Not Disposition. Findings suggest that gratitude for women with RA is not a stable trait or natural emotional response but rather something actively constructed, effortfully maintained, and frequently interrupted. Critically, acceptance of an RA diagnosis emerged as a sequential prerequisite for accessing gratitude rather than a parallel process, with premature gratitude carrying the risk of virtue bypass. Together, these manuscripts argue for a more nuanced, sequentially informed approach to gratitude intervention design and clinical application within chronic illness populations, with particular attention to the relational, cultural, and gendered dimensions of women’s experiences.