Service-learning is one way to engage students in health professions and promote health literacy in the community. This paper describes developing and delivering a service-learning course designed to improve diabetes literacy and diabetes outcomes among a medically underserved population. The didactic component of the course introduced topics such as health literacy, health education techniques, and diabetes pathophysiology, prevention, and treatment. Later, students designed and delivered community diabetes education classes at a local free clinic. After the classes were offered, diabetes knowledge and self-efficacy scores improved for community members and students leading the classes. A subset of community members also had lower body mass index at a 6-month follow-up. Though COVID-19 interfered with student's ability to offer in-person education sessions in the last semester this course was offered, it provided an opportunity to examine differences in diabetes knowledge and self-efficacy scores between students who offered in-person courses versus those who were unable to go out to the community and developed an online class instead. Self-efficacy was significantly higher at the end of the semester compared to at the end of the didactic component of the class for only those students who delivered in-person community education and not for those who developed the online class, providing further evidence of the benefit of engaging with community members on student outcomes. Community members and students alike were delighted with the program. Student-led community classes can be a financially sustainable solution to improving health literacy that benefits community members and students alike.