木星拥有67颗已确认的天然卫星，是太阳系内拥有最大卫星系统的行星。当中最大的4颗，统称伽利略卫星，由伽利略于1610年发现，这是首次（除了月球）发现不是围绕地球或太阳的天体。19世纪末起，越来越多更小型的木星卫星被发现，并命名为罗马神话中的诸神之王朱庇特（或同等的宙斯）的各位情人、倾慕者和女儿。

木星的卫星之中有8颗属于规则卫星，它们顺行的轨道几乎呈正圆，相对木星的赤道面倾斜度近乎零。其中的4颗伽利略卫星都是近球体，因此如果它们直接围绕太阳公转，便会被归为矮行星。其余4颗体积更小，更接近木星，是木星环尘埃的主要来源。

There are 67 known moons of Jupiter. This gives Jupiter the largest number of moons with reasonably secure orbits of any planet in the Solar System. The most massive of them, the four Galilean moons, were discovered in 1610 by Galileo Galilei and were the first objects found to orbit a body that was neither Earth nor the Sun. From the end of the 19th century, dozens of much smaller Jovian moons have been discovered and have received the names of lovers, conquests, or daughters of the Roman god Jupiter or his Greek equivalent Zeus. The Galilean moons are by far the largest and most massive objects in orbit around Jupiter, with the remaining 63 moons and the rings together comprising just 0.003% of the total orbiting mass.