Bobby soxer is a 1940s sociological coinage denoting the fans of Swing music and its creators like singer Frank Sinatra, the first singing teen idol. They were zealous, usually teenage and young adult girls from about 12 to 25. Fashionable adolescent girls wore poodle skirts and rolled down their socks to the ankle. In high schools and colleges, the gymnasium often was used as a dance floor; however, since street shoes and street detritus might damage the polished wood floors, the students were required to remove their shoes and dance in their bobby socks; thus the phrase 'sock hop'.
The adolescent actress Shirley Temple portrayed said type of impressionable adolescent girl in the film, The Bachelor and the Bobby-Soxer (1947).