This study reports dietary behaviors of adolescents in the Qassim region, Saudi Arabia, and comparison of these behaviors between cities with and without the Healthy Cities Program (HCP). We surveyed 1133 school-attending adolescents aged 15–19, using a multi-staged cluster sampling with probability proportionate to size. Prevalence of daily breakfast consumption was 27.7% among the adolescents. Prevalence of daily vegetables, fruits and milk or milk products consumption was 35.9%, 28.6% and 51.1%, respectively. Meanwhile, the prevalence of daily consumption of fast-food and carbonated drinks was 7.5% and 37.1%, respectively. There was no significant association between living in the healthy cities and daily intake of breakfast (OR: 1.15, 95% CI: 0.87–1.53), fruits (OR: 1.02; 95% CI: 0.77–1.36), vegetables (OR: 1.27; 95% CI: 0.98–1.67), or milk/milk products (OR: 1.0; 95% CI: 0.77–1.29); and the daily intake of fast-food (OR: 0.81; 95% CI: 0.49–1.35) or carbonated drinks (OR: 0.80; 95% CI: 0.60–1.05). These findings warrant further in-depth evaluation of the HCP in the Qassim region of Saudi Arabia.