Che is a Spanish expression commonly used in Argentina. It is an exclamation, often used to get attention or express surprise, and so it is similar, in some way, to exclamations such as "hey!" or "wow!". It is also used meaning "friend", and thus, it corresponds to expressions such as "mate", "pal", "man", or "dude" that are frequently used by English speakers.

Like these words, it may be used both at the beginning or at the end of a phrase: "Man, this beer is good" or "Let's go get a beer, man." ("¡Che, está buena la cerveza, or "¡Vamos a buscar una cerveza, che!")

The origen of this word is not clear as there are many theories. It may have derived from several native South American languages: in Guaraní, che means simply "I" or "my"; in Tehuelche and Puelche languages che means "man"; and in Mapudungun it means "people". Others, however, argue that the word che is derived from Spanish, from the archaic word ce, used to call someone's attention.