The marimba ( pronunciation (help·info)) is a musical instrument in the percussion family. It consists of a set of wooden bars with resonators. The bars are struck with mallets to produce musical tones. The bars are arranged as those of a piano, with the accidentals raised vertically and overlapping the natural bars (similar to a piano) to aid the performer both visually and physically. This instrument is a type of xylophone, but with broader and lower tonal range and resonators.

The chromatic marimba was developed in Guatemala from the diatonic marimba. Modern uses of the marimba include solo performances, woodwind ensembles, marimba concertos, jazz ensembles, marching band (front ensembles), drum and bugle corps, and orchestral compositions. Contemporary composers have utilized the unique sound of the marimba more and more in recent years.

Marimba bars are typically made of either wood or synthetic material, rosewood being the most desirable. Padouk is commonly used as a more affordable alternative. Bars made from synthetic materials generally fall short in sound quality in comparison to wooden bars, but are less expensive and yield added durability and weather resistance, making them suitable for outdoor use; marimbas with wooden bars are usually played inside because the bars are susceptible to pitch change due to weather. Bubinga and mahogany have also been cited as comparable to rosewood in quality for use as marimba bars. The specific rosewood used is universally from Honduras, Dalbergia stevensonii. This wood has a Janka rating of 2200, which is about three times harder than Silver Maple. The bars are wider and longer at the lowest pitched notes, and gradually get narrower and shorter as the notes get higher. During the tuning, wood is taken from the middle underside of the bar to lower the pitch. Because of this, the bars are also thinner in the lowest pitch register and thicker in the highest pitch register.