The xylorimba (sometimes referred to as xylo-marimba or marimba-xylophone) is a pitched percussion instrument similar to an extended-range xylophone with a range identical to some 5-octave celestas or 5-octave marimbas, though typically an octave higher than the latter. Despite its name, it is not a combination of a xylophone and a marimba; its name has been a source of confusion, as many composers have called for a 'xylorimba', including Alban Berg, Pierre Boulez and Olivier Messiaen, but for parts requiring only a four-octave xylophone(Blades and Holland n.d.). However, Pierre Boulez wrote for two five-octave xylorimbas in Pli selon pli(Blades and Holland n.d.).

Like the xylophone and marimba, the xylorimba consists of a series of wooden bars laid out like a piano keyboard "with a compass sufficiently large to embrace the low-sounding bars of the marimba and the highest-sounding bars of the xylophone." The lower notes of the xylorimba are described as sounding closer to a xylophone than a marimba, on account of its bars being both thicker and narrower, and due to the different size and shape of its resonators; the size and shape of the bars differs to emphasize different overtones(Blades and Holland n.d.).

The xylorimba experienced its greatest popularity in the 1920s and 30s, particularly within vaudeville theatre(Blades and Holland n.d.).