A percussion instrument of African and Latin American origin, the marimba is a member of the xylophone family with full length resonators below each bar. These can be tuned aluminium or other metal or simply hollowed-out gourds. The bars are usually made of rosewood or a newer synthetic material. They are supported at their nodal points by cords that run along the axis of the instrument, and the cords in turn are supported on wood or metal "fingers" that stick up from the top of the instrument.

On modern instruments the bars or "keys" are arranged much as they are on a piano: the bars for the sharps and flats (corresponding to the black piano keys) are in a second row further from the player and slightly above the row of bars representing the natural notes (the white keys on a piano.

The marimba is played by striking the bars with mallets which come in a wide variety of shapes, coverings, weights, and sizes. Each imparts the instrument with a different timbre, as does the player's technique. Some mallet heads are simply made of rubber or other synthetics graduated in hardness from soft to hard. Other mallet heads consist of a core covered with yarn, cord, or rubber. By controlling the core and winding a large variety of timbres are possible. Handles are usually made of birch, rattan, or fibreglass.

The marimba is part of an important musical tradition that extends from central Mexico to the northern part of South America. Xylophones were first brought to Latino communities by African slaves during the Spanish conquest of the 16th and 17th centuries. Marimbas that sonically and physically resemble an elongated piano keyboard were manufactured by the late 1890s. These beautiful instruments are characteristic particularly of the mountainous Chiapas region of southern Mexico; often, three or more performers play as an ensemble on one instrument.

Long underappreciated elsewhere, the marimba has begun to be incorporated into mainstream classical and popular music in the United States, Canada, and Europe in recent years, including many arrangements of piano and guitar music for marimba.