The usual English-language name for a girl celebrating her fifteenth birthday in the tradition is quinceañera.
In Spanish, quinceañera can refer to the young woman who reaches 15, while English commonly extends the word to the celebration itself. The masculine counterpart quinceañero exists in Spanish, although the traditional ceremony and the word’s widespread popular use have historically centered on girls.
The term is more specific than “birthday girl.” It points to a cultural milestone that may involve family rituals, formal clothing, music, a reception, and sometimes a religious service. None of those elements is mandatory in every family, however, and the event can be adapted to local customs or personal preferences.
Quinceañera is also not a synonym for “debutante.” A debutante historically refers to a young woman being formally introduced to society, while a quinceañera centers on the fifteenth birthday. Likewise, it is distinct from the North American “sweet sixteen,” which marks a different age and cultural tradition.