A tiara may be placed on a quinceañera’s head to symbolize royalty.
The crowning ceremony presents the honoree as a young woman with dignity and importance. A parent, sponsor, or other family member may place the tiara during the formal portion of the celebration, depending on local custom.
The accessory is often jewel-like and may match the dress or other decorations. In everyday descriptions, people sometimes call it a crown, but a tiara is the more specific term for the ornamental headpiece traditionally associated with many quinceañeras.
This rite is not mandatory. Quinceañera customs vary by region and family, and a modern celebration may use a simpler hair accessory or skip the crowning altogether.