Few studies have assessed total water intake in European children and adolescents, and fewer have evaluated the types of beverages being consumed in relation to childhood obesity and sedentary behaviors. Water intake and beverage consumption in the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-sectional Study, a large, pan-European study in adolescents aged 12.5 to 17.5 years, are described in terms of gender and age differences and in relation to screen-based sedentary behaviors. Dietary intake was measured in terms of fluids (milliliters) and energy (kilojoules) using two 24-hour recall assessments in 2741 adolescents. Sugar-sweetened beverages accounted for the largest amount of energy intake per person from beverages, and water, the largest amount of fluid. However, 12.1% of adolescents did not drink plain water at any time, with 69.4% of boys and 64.4% of girls having a total water intake below the levels currently recommended by the European Food Safety Authority. A causal link between sweetened beverage consumption and childhood obesity has not been definitively shown; however, the consumption of sugar-sweetened beverages during sedentary activities could contribute to the promotion of childhood obesity. In general, adolescents spending more than 4 h/d on sedentary behaviors were more likely to consume sweetened beverages than those spending fewer than 2 hours on the same activities. Efforts should be made to promote healthy foods and beverages in children and adolescents and to replace sedentary behaviors with physical activity.