Luminaria is a term used in different parts of the world to describe various types of holiday lights, usually displayed during Christmas. In English, the term most commonly refers to a specific type of simple paper lantern made by placing a votive candle in some sand inside a paper bag. Also known as a farolito, it is a traditional Christmas decoration in the Southwestern United States, particularly New Mexico, where it is a cultural hallmark of the Pueblos and Hispanos of New Mexico and a part of the state's distinct heritage. Luminarias are usually placed in rows along walls, roofs, and walkways to form a holiday display, especially on Christmas Eve.

Electrically-lit luminarias are also used, consisting of a string of standard incandescent "Christmas lights" with the bulbs covered with a tan plastic sleeve, made to about the size and shape of a small paper bag.

In Northern New Mexico, luminaria can also refer to a small stacked-wood bonfire, an older tradition which has been replaced to some extent by the paper luminarias. Residents of this region typically call the paper lanterns farolitos in order to distinguish the two types of illumination. Use of the word luminaria for paper lanterns is considered incorrect by some New Mexicans and is a frequent topic of debate.

Yet another form of luminaria, a small torch or large candle, is carried by the leader of the procession of Las Posadas, a nine-day holiday running December 16–24.

In non-English-speaking countries such as Italy, Spain, and Japan, luminaria is used in a much more general sense to describe any type of festive light display, including bonfires, candles, and electric lights.