Legerdemain is a set of techniques used to create illusions for magic or card tricks. It is more commonly called sleight of hand and sometimes prestidigitation. Legerdemain comes from the French for "lightness of the hand."

Legerdemain is one of the most difficult skills for the magician to perfect, but also one of the most impressive. It is absolutely necessary for most close-up magic tricks, though many stage magicians make use of legerdemain as well. Magic tricks that use legerdemain often involve props, such as cards or coins, that the magician manipulates in a surprising way, hopefully without the audience being able to see how it is really done.

In practice, legerdemain is much more than an agile hand. Close-up magicians and other legerdemain artists often rely heavily on misdirection, in which the audience is manipulated into looking in a certain direction, freeing the magician to perform tricks outside of their gaze. Mastering misdirection is often the most challenging and the most rewarding part of becoming a successful legerdemain artist. The expert in legerdemain is able to execute highly choreographed tricks with apparent ease and naturalness.

Though legerdemain is often used to entertain, it can also be used to take advantage of people. Legerdemain can give a card player an unfair edge over the competition and is considered a form of cheating in games of luck. Some people use legerdemain to con tourists out of money, as in the well-known three-shell game. Pickpockets, sometimes working in teams, are also notoriously skilled in legerdemain.

Spirit mediums during the seance craze around the turn of the 20th century were often accused of faking results through legerdemain, and many were exposed in this practice. In fact, many of the modern magician's tricks have their roots in the heyday of the seance. Legerdemain can take years to master, but the aspiring magician can find many books, classes, and websites on the basics.