Background: Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycemia and glucose intolerance, which may lead to various complications, including diabetic foot ulcers. Inadequate foot care practices among patients with DM remain a significant concern and may increase the risk of foot injuries and infections. Objective: This study aimed to identify factors associated with foot care behavior among patients with DM at the Bakauheni Health Center, South Lampung. Methods: This study employed a quantitative, descriptive observational analytic design with a cross-sectional approach. The sample consisted of 91 respondents selected through a purposive sampling technique. Data collection was conducted at the Bakauheni Health Center. The research instrument used was the HDFSS & NAFF questionnaire to measure family support and foot care behavior. Results: The results showed that the majority of respondents were female (60.4%), in the late elderly group (41.8%), and had a basic level of education (84.6%). Most respondents reported high family support (51.6%) and demonstrated good foot care behavior (79.1%). Bivariate analysis using Kendall’s Tau-b test revealed a significant correlation between duration of illness and family support with foot care behavior in DM patients (p < 0.05). Furthermore, ordinal logistic regression analysis indicated that family support was the most influential factor affecting foot care behavior (p = 0.037; OR = 4.039). Conclusion: In conclusion, family support plays a crucial role in improving foot care behavior among patients with DM. It is recommended that healthcare teams, particularly community nurses, involve family members to enhance adherence to foot care practices and prevent diabetic foot complications.