How many moons are there on Jupiter?

63.

In the book “Jupiter and How to Observe It”, the author John W. McAnally mentions Jupiter has 63 known moons (or satellites). The four largest moons were discovered by Galileo, in 1610 ‘“ they are known as Galilean moons: Io, Europa, Callisto and Ganymede. These four moons have diameters that vary from 3,130 km (Europa) to 5,268 km (Ganymede).