Background Diabetic foot ulcers (DFUs) are one of the most common and fatal complications of diabetic patients with uncontrolled diabetes mellitus (DM) that may end with their feet amputation. These complications can be prevented through the adherence of diabetic patients to their diabetes management plan and by educating them about risk factors, complications of diabetic foot, and proper foot care. To develop effective health education programs to educate diabetic patients and caregivers regarding diabetic foot and its effective care, we should first identify gaps in patients' knowledge and perception of diabetic foot and evaluate their practice of foot care. Objectives This study aimed to evaluate knowledge and attitude toward DFUs and the practice of foot care among adult diabetic patients attending Al-Qunfudah Diabetes Center, Saudi Arabia, from October 2022 to March 2023. Methods A total of 403 adult diabetic patients were recruited in this cross-sectional study during their attendance at the diabetes center in Al-Qunfudah district, Saudi Arabia. The study researchers conducted a physical face-to-face interview with each diabetic patient using a validated questionnaire with closed-ended questions to collect their responses regarding their knowledge and attitude toward DFUs and their behavior toward foot care. The collected data were analyzed using IBM SPSS Statistics for Windows, version 23 (released 2015; IBM Corp., Armonk, New York, United States). Results Out of 403 diabetics, 50.4% (n = 203) had inadequate knowledge (knowledge score < 80%), 46.4% (n = 187) had negative attitudes (attitude score < 80%) toward DFUs, and the majority could not practice foot care well, with 77.7% (n = 313) giving a practice score less than 80%. Seventy patients (17.4%) self-reported a history of DFUs. Predictors of good knowledge about DFUs among diabetics include age between 30 and 59 years (odds ratio (OR) = 2.942, confidence interval (CI) 95% = 1.695-2.107, p < 0.001), marriage (OR = 3.101, CI 95% = 1.893-5.079, p < 0.001), working (OR = 5.325, CI 95% = 3.019-9.389, p < 0.001), diploma education (OR = 8.205, CI 95% = 3.332-20.203, p < 0.001), managing DM with oral drugs (OR = 2.219, CI 95% = 1.399-3.519, p < 0.001), and having no DFUs (OR = 2.712, CI 95% = 1.557-4.723, p < 0.001). Males were more likely to practice foot care well (OR = 1.925, CI 95% = 1.142-3.245, p = 0.013). Primary education (OR = 3.421, CI 95% = 1.655-7.073, p < 0.001) predicted appropriate foot care. Patients with DM for one to five years (OR = 1.995, CI 95% = 1.139-3.493, p = 0.016) and those on diet and metformin (OR = 2.133, CI 95% = 1.134-4.011, p = 0.019) were expected to have better foot care than other diabetics. Conclusion Diabetic patients in the Al-Qunfudah district of Saudi Arabia had inadequate knowledge and negative attitudes toward DFUs, and their foot care behaviors were inadequate. Furthermore, DFUs were self-reported in around 17% of diabetic patients. Specialized training programs are recommended to enhance knowledge regarding DFUs among diabetics and motivate and train them and caregivers on how to conduct proper foot care. These educational programs should target all diabetics, with an emphasis on those with DFUs, females, non-working patients, individuals who have had DM for a longer time, and illiterate diabetics. To understand the factors behind patients' negative attitudes toward diabetic foot, future qualitative research is required.