Because of its composition, ultra-processed foods can contribute to excess weight. The objective of the study was to verify the association between the consumption of ultra-processed foods and overweight in adolescents. We conducted a cross-sectional study with 617 adolescents. Sociodemographic, anthropometric and food consumption data were evaluated. Linear regression analyses were used to verify the association. Ultra-processed foods presented higher proportions of carbohydrates, lipids and saturated fat in relation to the total diet consumed. However, this food group had a lower proportion of proteins and fibers. Intake of ultra-processed foods was more frequent in females and being overweight was positively associated with the ingestion of ultra-processed foods. The high consumption of ultra-processed foods can contribute to weight gain. Therefore, the reduction of consumption of ultra-processed foods should be encouraged to improve eating habits.