Not to be confused with the similarly named marimba, the marimbaphone is an obsolete tuned percussion instrument, developed in Chicago in the early 20th century.

The marimbaphone had either shallow steel or wooden bars arranged chromatically with a tube resonator under each bar. Its timbre was similar to the celesta and it was used mainly by marimba bands and as a solo instrument by stage artists.

In addition to being played with mallets in the conventional way (as in the playing of a marimba or vibraphone), the marimbaphone was designed so that its bars could be rotated from a horizontal to a vertical position, allowing them to more easily be played with a bow. To further facilitate bowing, the ends of its bars were concave rather than flat. A single marimbaphone could be played by more than one performer, allowing both techniques to be used simultaneously.