The dollar sign, also known as peso sign, is a symbol consisting of a capital "S" crossed with one or two vertical strokes ($ or depending on typeface), used to indicate the unit of various currencies around the world, including most currencies denominated "peso" and "dollar". The explicitly double-barred sign is called cifrão in Portuguese.

The sign is also used in several compound currency symbols, such as the Brazilian real (R$) and the Nicaraguan córdoba (C$).

The one- and two-stroke version are often considered mere stylistic (typeface) variants, although in some places and epochs one of them may have been specifically assigned, by law or custom, to a specific currency. The Unicode computer encoding standard defines a single code for both.

In most English-speaking countries that use that symbol, it is placed to the left of the amount specified, e.g. "$1", read as "one dollar".