Adolescents face the risk of the triple burden of malnutrition-the co-existence of micronutrient deficiencies, underweight and overweight and obesity and related noncommunicable diseases. Poor-quality diets are a modifiable risk factor for all forms of malnutrition in adolescents. However, there is limited knowledge about diet quality for African adolescents. We analyzed data from 4609 school-going adolescents aged 10-15 years in Burkina Faso, Ethiopia, Sudan and Tanzania. Dietary intake was assessed using food frequency questionnaires, and diet quality computed using the Global Diet Quality Score (GDQS). Generalized estimating equations linear regression models were used to evaluate factors associated with adolescent diet quality. Mean adolescent age was 12.4 (±1.4) years and 54% of adolescents were female. Adolescents reported physical activity on 1.5 (±1.7) days/week. The mean GDQS (±SD) was 20.6 (±4.0) (maximum 40). Adolescent consumption of vegetables, fruit, nuts and seeds, eggs, fish and poultry was low, and refined grain consumption was relatively high. Boys consumed unhealthy foods less frequently but consumed fewer cruciferous vegetables and deep orange tubers. Older adolescents had higher fish and lower red meat consumption. Having an unemployed mother versus farmer (estimate -2.60, 95% confidence interval [CI]: -4.81, -0.39), and having 3-4 days of physical activity per week versus none (estimate 0.64, 95% CI: 0.11, 1.17) were associated with GDQS. We found evidence of poor-quality adolescent diets and gender and age differences in the consumption of healthy diets. Programs to address poor-quality diets should consider tailoring interventions for adolescent girls and boys of different ages and also consider the role of physical activity in these contexts.