Purpose: This study explored the physical availability of alcoholic beverages to adolescents through online liquor sales, based on a semantic network analysis. Method: Two methods were used: 1) first, an experimental study was conducted of 300 restaurants with app and phone delivery to verify whether the IDs of adolescents were checked when purchasing alcoholic beverages; then, 2) focus group interviews with two groups (adolescent drinkers and adolescent non-drinkers) were carried out to explore characteristics of the physical availability of alcoholic beverages to adolescents, drinking motives, alcohol advertising, and drinking behaviors. Differences in ID checks in the Seoul area, delivery application type, day of the week, and delivery food type were analyzed using a frequency analysis test. A semantic network analysis was used to investigate the relationship between keywords. The network characteristics were identified using a community analysis. Results: Only 14.7% of online sales checked whether an ID or guardian was present. Thirty-seven and 20 meaningful keywords were extracted from the texts of adolescent drinkers and non-drinkers, respectively, and the community analysis revealed four sub-communities: 1) peer inluences, alcohol advertisement, physical availability of alcohol, and liquor sales for adolescent drinkers and 2) physical availability of alcohol, Alcohol temptations, alcohol-related images, and online liquor sales for non-drinkers. Keywords gave the impression of a tolerant drinking culture. The adolescents’ alcohol use was associated with the ease of physically obtaining alcohol, their positive perceptions of alcohol, family factors, peer influences, and social and cultural aspects of alcohol consumption in general. Although alcohol should not be explicitly sold to adolescents, the results of this study confirmed that it was easy for adolescents to purchase alcoholic beverages. They also confirmed that the main channel for adolescents to experience drinking or to come into contact with alcoholic beverages was the family environment, i.e., their parents’ tolerant attitude toward alcohol. Conclusion: Therefore, for the prevention of drinking among adolescents, targeting only adolescents is not effective, and a campaign to raise awareness and change the overall drinking culture of society is needed.