Sweet 15 is an English-language nickname for a quinceañera commonly used in the United States.
The phrase is modeled on “Sweet 16,” the familiar American birthday milestone, but it uses 15 because the quinceañera tradition centers on the fifteenth birthday. English-language families may use Sweet 15, quince, quinceañera, or quince años, sometimes using more than one term for the same event.
Sweet 15 is a popular label, not a separate ceremony with its own universally fixed rules. A celebration using that name may include a formal dress, court, dance, cake, reception, religious service, or none of those elements. Terminology often reflects a family’s language and community, while the details reflect personal preference and regional custom.