Hypertension has been identified as the most prevalent chronic disease, accounting for the majority of premature deaths in people with physical disability in South Korea. Self-care is vital in controlling high blood pressure. Health literacy has been implicated in self-care behaviors; however, the mechanisms behind this relationship remain unclear. Therefore, the present study aimed to test a hypothetical path model estimating the association between health literacy and hypertension self-care behaviors and to verify the mediating effects of access to healthcare, provider–patient interactions, hypertension knowledge, and hypertension control self-efficacy in hypertensive people with physical disability. In total, 211 hypertensive adults with physical disability completed an online survey. A path analysis using a multi-mediation model was performed using AMOS 17.0 (IBM SPSS Inc., Chicago, IL, USA), and indirect effects were estimated using phantom variables. As a result, the model fit indices were deemed excellent. Significant indirect pathways were determined from health literacy to hypertension self-care behavior via provider–patient interactions, knowledge, and self-efficacy, although no direct association was found between health literacy and self-care behaviors. The study findings supported the importance of provider–patient interactions, knowledge, and self-efficacy, which play a role in linking health literacy and self-care behavior in hypertensive patients with physical disability.