A quinceañera is traditionally celebrated when a girl turns 15.
The Spanish word quinceañera refers both to the celebrant and, commonly, to the birthday celebration itself. The number comes from quince, meaning “fifteen,” and the event marks a transition from childhood toward young womanhood in many Latin American and Latino communities.
The tradition is especially associated with Mexico, Central America, South America, the Caribbean, and Latino communities in the United States. Customs vary widely by family, country, religion, and budget. Some celebrations include a formal dress, a choreographed dance, a court of attendants, a family reception, and a religious service.
Turning 15 does not have the same legal significance everywhere, and the celebration is not identical across Spanish-speaking cultures. It is better understood as a cultural coming-of-age tradition than as a universal legal or religious requirement.