木琴（英语：Xylophone）是打击乐器的一种。将木制琴键置于共鸣管之上，以琴棒敲打以产生旋律。琴键排列方式类似于钢琴键盘。一般所指的木琴为高音木琴，琴键较窄，音域较高，音色清脆。常见的木琴还有马林巴，琴键从高音窄到低音宽，音域较广，音色圆润。

木琴的起源仍未能确定，最早的历史记载，大约出现于公元9世纪。当时已经发人类懂得以不同大小的木棒排列在架上，然后用棍敲打的乐器存在。例如印尼的甘美兰，便有以木片制成的琴；而非洲亦有非洲木琴（Balafon），将葫芦削顶后套在木棒之下制成共鸣器，可以讲是现代木琴的雏型。

The xylophone (from the Greek words ξύλον—xylon, "wood" + φωνή—phōnē, "sound, voice", meaning "wooden sound") is a musical instrument in the percussion family that consists of wooden bars struck by mallets. Each bar is an idiophone tuned to a pitch of a musical scale, whether pentatonic or heptatonic in the case of many African and Asian instruments, diatonic in many western children's instruments, or chromatic for orchestral use.