Gait speed declines at a faster rate in persons with HIV (PWH) than in the general population but the risk factors associated with this decline are not well understood. In the AIDS Clinical Trials Group (ACTG) A5322 (HAILO, HIV Infection, Aging, and Immune Function Long-term Observational Study), an observational cohort study of PWH ≥40 years of age, those who developed slow gait during the first 3 years of follow-up were compared with persons who maintained normal speed. Associations with demographic and clinical covariates were assessed using multivariable logistic regression. Of 929 participants, 81% were men, 31% Black, and 20% Hispanic. Median age was 51 years [interquartile range (IQR) = 46-56]. At study entry, 92% had plasma HIV RNA <50 copies/mL with median CD4 count 631 cells/mm3 (IQR = 458-840). At study entry, 7% of participants had slow gait, 16% had neurocognitive impairment (NCI), and 12% had diabetes. Over 3 years, 87% maintained normal gait speed, 3% maintained a slow gait, 6% developed a slow gait, and 4% improved from slow to normal gait speed. In multivariable models, hemoglobin A1C (HbA1C) percentage, per one unit increase [odds ratio (OR) = 1.36; 95% confidence interval (CI) = 1.03-1.81; p = .033], NCI (OR = 3.47; 95% CI = 1.57-7.69 p = .002), and black versus white race (OR = 2.45; 95% CI = 1.08-5.59; p = .032) at entry were significantly associated with development of slow gait compared with those maintaining normal gait speed. The association between baseline HbA1C and development of slow gait speed highlights an intervenable target to prevent progression of physical function limitations.