The tilde distinguishes the Spanish spelling “quinceañera” from “quinceanera.”
The mark appears above the letter ñ, creating a separate Spanish letter and the sound represented by “ny” in many English transliterations. The standard Spanish spelling is quinceañera, with ñ rather than a plain n.
English-language writing often drops the tilde because some keyboards, search systems, or publishing styles make accented characters less convenient. “Quinceanera” remains recognizable, but it is an unaccented spelling rather than the standard Spanish form.
The tilde is not an accent mark showing stress in this word. It is part of ñ itself, a letter with its own history in Spanish orthography. Similar spelling distinctions occur in names and words borrowed from Spanish, so preserving the ñ can improve accuracy and pronunciation.