Autism Spectrum Disorder (ASD) has been frequently associated with an increased risk of obesity and metabolic disorders, including dyslipidaemia. However, research on lipid profiles and dietary intake in this population remains scarce. This cross-sectional study aimed to evaluate dietary patterns and their association with serum lipid profile in children and adolescents diagnosed with ASD. The study included 233 individuals from 2 to under 19 years assisted by the public health system in Pelotas, Brazil. Fasting blood samples were collected and analysed for serum concentrations of total cholesterol (TC), HDL-C, LDL-C, and triglycerides (TG). Dietary intake was assessed using three non-consecutive 24-hour food recalls (two weekdays and one weekend day). Dietary patterns were derived through reduced rank regression, using food group intakes as predictors and fibre density, energy density, carbohydrate, and saturated fat intakes as response variables. Standardised pattern scores were calculated to assess individual adherence, and linear regression models, adjusted for potential confounders, were applied to examine the association between the dietary pattern scores and lipid profiles. Elevated TG concentrations were observed in 48.9% of the participants. Four dietary patterns were identified: Healthy, Sugar and Starches, Mixed and Dairy and Biscuits. After adjustment, no significant associations were observed between dietary pattern scores and lipid profile. These findings underscore the complex nature of lipid metabolism in individuals with ASD, and suggest that dietary patterns alone may not fully explain variations in lipid profiles. This reinforces the need for further research and development of appropriate nutritional interventions for this population.