A saltire is an X-shaped figure in heraldry. It usually occupies the entire field in which it is placed.

A saltorel is a narrow saltire; the term is usually defined as one-half the width of the saltire.

A saltire couped, when the principle charge only occupies the middle part of the field, without extending to the edges.

A field that is party per saltire is divided into four areas in an x-shape. If two tinctures are specified, the first refers to the areas above and below the X, and the second refers to the ones on either side. Otherwise, each of the four divisions may be blazoned separately.

When charges are blazoned as "in saltire" there are two generally possibilities. When there are two such charges, they are crossed in an "X"; otherwise, five or more charges are arranged in an X-shaped pattern (obviously five or more are necessary for this to be feasible).

A saltire is used by a supporter of the royal arms in Scotland, and the Scottish flag is a blue field with a white saltire; it represents Saint Andrew, the patron saint of Scotland, who is supposed to have been crucified on a cross of that shape. Because of its use in the Scottish arms and flag, the saltire appears in the Union Flag and the arms and flag of Nova Scotia. The phrase "The saltire" is sometimes used in patriotic literature to refer to the Scottish flag.