Food neophobia is a reaction of dislike or fear of food, which may be due to a wide variety of factors (taste, texture, exposure at an early age, genetics, or diversity in feeding practices and food consumption). The aim of this study was to assess the preferences for tastes and foods and food neophobias among Spanish adolescents and to compare the differences between boys and girls. This was a cross-sectional observational study on 11–18-year-old healthy adolescents (n = 600; 50% female) recruited in the Castilla–La Mancha region (central Spain). Information on taste preferences, food neophobias, anthropometric measurements, and sociodemographic data was recorded. The highest taste preference was found for sweet, salty, and umami. Most adolescents usually did not try new foods outside the home, nor did they like to try foods from other countries. More than half of them also acknowledged being selective eaters or were very particular about the foods they ate. There were no significant associations between taste preference and neophobias with obesity, waist-to-height ratio (WtHR), sleep, and smoking. Adolescents showed a high unwillingness to change food habits, and most of the food neophobias found in the current study were related to new, novel, or previously unknown foods. Spanish adolescents from central Spain (Castilla–La Mancha region) showed a preference for sweet, salty, and umami tastes of foods, as well as food neophobia towards foods that they do not regularly consume, mainly those with a bitter taste. Gender and body weight showed little influence, and age had a moderate influence on food neophobias. Familiarity with foods, as well as educational activities, are suggested as useful to decrease food neophobias among adolescents.