The consumption of ultra-processed foods (UPF) has increased over the past few decades. However, few studies have investigated the association between UPF consumption and cardiometabolic risk factors in adolescents from developing countries. To evaluate the association between UPF consumption and cardiometabolic risk factors in Brazilian adolescents. This study included students aged 12-17 years who participated in the ERICA. Food consumption was assessed using a 24-h food recall, and the foods were classified based on their degree of processing, utilizing the NOVA classification. Participants' blood samples were collected after an overnight fast and exams were performed (triglycerides, total cholesterol, HDL-c, LDL-c, fasting glucose, insulin, and HbA1c). Overweight/obesity and blood pressure were also investigated. Associations were evaluated using Poisson regression models. The analysis included a total of 36,952 adolescents. The energy consumption from UPF was 30.7% (95%CI: 29.7-31.6) per day. Adolescents with high UPF consumption, defined as the top tertile (≥38.7% per day), were observed to have higher intake of sodium, saturated and trans-fat, while having lower intake of proteins, fibers, polyunsaturated fats, vitamins and minerals. After adjusting for potential confounders, it was observed that higher UPF consumption was directly associated with high LDL-c (PR = 1.012; 95%CI: 1.005-1.029) and inversely with low HDL-c (PR = 0.972; 95%CI: 0.952-0.993). No associations were found between UPF consumption and other cardiometabolic risk factors. Brazilian adolescents have presented a high consumption of UPF, which is associated to poor diet quality and can contribute to elevated LDL-c levels.