27 is an American rock band from Cambridge, Massachusetts. 27 was formed by Maria Christopher, formerly of Dirt Merchants, and Ayal Naor in 1997. 27 is commonly categorized as a rock or indie rock band, but the genres lo-fi and emo have occasionally been used to describe them.

27 has toured extensively throughout Europe, North America, and Japan. In the Czech Republic, 27 opened for Robert Plant.