The aim of the current study was to examine the association between dietary patterns and health-related quality of life (HRQoL) among Spanish children and adolescents. A modified version of the parental version of 10 items of the Screening for and Promotion of Health-Related Quality of Life in Children and Adolescents-a European Public Health perspective (KIDSCREEN-10) was used to assess children's HRQoL in three areas: subjective physical, mental, and social status. To evaluate dietary habits, a food frequency questionnaire was employed. To identify different feeding patterns in the sample of children and adolescents examined, cluster analyses were carried out. In addition, a generalized linear model with a Gaussian distribution was applied to test the associations between the determined clusters and HRQoL. The lowest HRQoL was identified in participants located in the unhealthiest cluster (Cluster 1) (mean [M] = 85.2; 95% confidence interval [CI] 83.7 to 86.7). In comparison with the unhealthiest cluster (Cluster 1), a greater estimated marginal mean of HRQoL was identified for participants in the moderately healthy cluster (Cluster 1) (p = 0.020) and in the healthiest cluster (Cluster 2) (p = 0.044). Based on our findings, dietary habits based on the low consumption of bread, cereals, and dairy products (mainly), together with low intake of fruits and vegetables, are related to lower HRQoL in children and adolescents. These results underscore the importance of promoting balanced and nutrient-rich diets among young populations. Public health initiatives should focus on educating parents, caregivers, and children about the benefits of a varied diet that includes adequate portions of fruits, vegetables, whole grains, and dairy products.