Béla Bartók's Mikrokosmos (Hungarian: Mikrokozmosz) Sz. 107, BB 105 consists of 153 progressive piano pieces in six volumes written between 1926 and 1939. The individual pieces progress from very easy and simple beginner études to very difficult advanced technical displays, and are used in modern piano lessons and education. In total, according to Bartók, the work "appears as a synthesis of all the musical and technical problems which were treated and in some cases only partially solved in the previous piano works." Volumes one and two are dedicated to his son Péter, while volumes five and six are intended as professionally performable concert pieces. Bartók also indicated that these pieces could also be played on other instruments; Huguette Dreyfus, for example, has recorded pieces from Books 3 through 6 on the harpsichord.

In 1940, shortly before they emigrated to the United States, he arranged seven of the pieces for two pianos, to provide additional repertoire for himself and his wife Ditta Pásztory-Bartók to play.