Unilateral offloading footwear prescribed to patients with diabetic foot ulcers elevates one limb relative to the other, which may lead to limp and abnormal gait. This study investigated whether the unilateral foot ulcer and offloading combination negatively impacts gait function beyond diabetic peripheral neuropathy.Eighty-six participants were recruited in 3 groups: 12 with diabetic peripheral neuropathy and unilateral foot ulcers wearing offloading footwear (offloading group, age = 55.6 ± 9.5 years, BMI = 30.9 ± 4.5 kg/m), 27 with diabetic peripheral neuropathy (neuropathy group, age = 64.3 ± 7.7 years, BMI = 30.9 ± 5.4 kg/m), and 47 non-diabetic controls (non-diabetic group, age = 62.9 ± 16.1 years, BMI = 29.0 ± 6.0 kg/m). Gait function was quantified during a habitual speed walking test using a validated wearable platform.The offloading group exhibited deteriorated gait function compared to the non-diabetic group (p < 0.005, Cohen's effect size d = 0.90-2.61). They also had decreased gait speed (p < 0.001, d = 1.79) and stride length (p < 0.001, d = 1.76), as well as increased gait cycle time (p < 0.001, d = 1.67) and limp (p < 0.050, d = 0.72-1.49) compared to the neuropathy group. The offloading group showed increased gait unsteadiness compared to the neuropathy group, but the difference did not reach statistical significance in our samples.This study demonstrated that while diabetic peripheral neuropathy deteriorates gait function, including increasing gait unsteadiness and limp, the diabetic foot ulcer and offloading combination magnifies the deterioration beyond diabetic peripheral neuropathy. These findings promote caution of the current standards of care for treating diabetic foot ulcers with offloading footwear. However, it is possible that a contralateral shoe lift may remedy deteriorated gait function and improve quality of life for unilateral offloading users.