"Four Letter Word" is the fourth single from English pop singer Kim Wilde's sixth studio album, Close (1988).

The song was issued as a single in November 1988, marking Wilde's last release of a track written by her father and brother, who had written the majority of her early hits together.

"Four Letter Word" became Wilde's third consecutive UK top-10 single from Close, reaching number six.

It also peaked within the top 10 in Belgium, Denmark, Ireland, and the Netherlands.

An extended version as well as a "late night" remix of "Four Letter Word" were released on the 12-inch and CD singles.