Technically a portable double inclined plane, a wedge is a simple machine used to separate two objects, or portions of objects, through the application of force, perpendicular to the inclined surfaces, developed by conversion of force applied to the blunt end. The mechanical advantage of a wedge depends on the ratio of it length to its thickness.

Examples include axes and nails. Knives and chisels can sometimes be used as wedges, however, they are more fundamentally cutting implements.

In mathematics, there is something called the wedge product in exterior algebra and the wedge sum in algebraic topology.

In science fiction and fantasy fandom, the term Wedge has been unofficially adopted to describe minor background characters that survive an entire saga or series without being killed. However, they tend to suffer notoriously from little to no character development. Yet, for all the lack of attention they get, they usually carry the reputation of being reliable, dependable, and competent. The term comes from the character Wedge Antilles who appeared in the three original Star Wars movies.

Other examples of Wedge type characters are

• Lt. (later Commander) Kyle (Star Trek)
• Lt. Nanbu and Lt. Ohta (Space Battleship Yamato) called Dash and *Eager in Star Blazers
• Chief Petty Officers Oscar Dublin and Mark Kran (Mobile Suit Gundam)
• 2nd Lt. Shigeru Aoba (Neon Genesis Evangelion)

In phonetics, wedge is a name commonly used for the open-mid back unrounded vowel, from its symbol in the International Phonetic Alphabet, .

A wedge as in golf clubs: Wedges are, of course, irons. But wedges are often talked about separately, placed in their own category, because they are specialized irons. When talking about the category of wedges, most golfers mean the gap wedge, sand wedge and lob wedge. Although a pitching wedge has "wedge" in its name, it is usually grouped with the other irons. This is because a typical, off-the-shelf set of irons for sale will include a 3-iron through a pitching wedge. The gap wedge, sand wedge and lob wedge are often sold separately, or as a 3-club subset. Because the focus with wedges is on accuracy - trying to hit a short shot as close as possible to the flagstick - wedges are often referred to as the "scoring clubs."