An iaito (居合刀, iaitō), also known as a mogito, is a Japanese practice sword with a dull edge, often used for studying the art of iaido. Most iaito are made of an aluminium-zinc alloy, which is often cheaper and lighter than steel, but that also meets the Japanese legal requirement of not being able to be used as a live blade. As such, they are made as practice weapons and are not suited for any type of contact. The best iaito are rather faithful reproductions of real swords with authentic weight, shape and similarly high-quality finish, and may even feature a mock hamon (the temper line of a live blade).

Many traditional swordsmiths located in Seki, Gifu Prefecture, produce iaito. Some dojos in Japan recommend that only iaito be used for practicing iaido, until the practitioner's skill is consistent enough to safely use a live blade or shinken. Many koryu require one to start with shinken right away, while some modern dojos prohibit the use of a live blade altogether.

The matching of sword length and weight to the practitioner's height and strength is of utmost importance in safely and accurately performing iaido waza or technique. Due to the repetition involved in the practicing of iaido, iaito are often constructed with the balance point of the blade being set further from the kissaki or blade point and closer to the tsuba or guard than live blades.

See also bokken and katana.