Disease burden linked to sub-optimal diets in Africa remains under-explored. Using data from the Global Burden of Disease 2021 study, we assessed the disease burden attributable to dietary risks across various locations, age groups, years, and sexes in Africa. Deaths attributable to sub-optimal diet increased from 0.35 million in 1990 to 0.64 million in 2021, and projected increased to 1.62 million in 2040. Disability-adjusted life years (DALYs) similarly increased from 9.79 million in 1990 to 18.1 million in 2021, projected to reach 45.6 million by 2040. In 2021, North Africa had the highest proportion of diet-attributable disease burden at 8.52%. The top dietary risk factors for mortality that year included low fruit intake, insufficient vegetable consumption, and inadequate whole grain intake. Cardiovascular diseases were the leading causes of diet-related deaths. The age-standardized rate of death and disability-adjusted life years linked to dietary risk factors were highest in the Central African Republic, Lesotho, and Guinea-Bissau. Furthermore, the disease burden was found to be greater in males compared to females. These findings will highlight the implementation of evidence-based dietary interventions in Africa.