Ultra-processed foods have been associated with increased risk of chronic disease, poor overall health and psychological outcomes. This study explored the association of ultra-processed foods with quality of life in adolescent girls from northeastern Iran. In an interdisciplinary cross-sectional study, n = 733 adolescent girls were recruited by random cluster sampling. Assessments were completed for demographics, physical activity, anthropometric and biochemical parameters, psychological health and dietary intake. The participants were categorized into quartiles of ultra-processed food intake, and multivariable logistic regression was used in several models to investigate the association between ultra-processed food intake and psychological health. The mean age of the participants was 14 years. There were no significant differences in participant demographics for the quartiles of ultra-processed food intake including weight, waist–hip ratio, waist circumference, depression, insomnia and cardiometabolic markers related to cardiovascular disease risk. Adjusted logistic regression showed participants in the highest category of ultra-processed food consumption had an increased likelihood of reduced quality of life (OR: 1.87, 95% CI: 1.13–3.11), with a greater chance for insomnia (OR: 4.04, 95% CI: 1.83–8.94) across all models. However, no significant associations were observed between consumption of ultra-processed foods and daytime sleepiness. We highlight the association between ultra-processed food consumption and poor quality of life and insomnia amongst adolescent girls. Large longitudinal integrated public health studies in different ethnicities are needed to confirm these associations and evaluate their possible impact for optimizing health promotion programs.