  A stellar occultation occurs when a Solar System object passes in front of a
star for an observer. This technique allows the determination of sizes and
shapes of the occulting body with kilometer precision. Also, this technique
constrains the occulting body's positions, albedos, densities, etc. In the
context of the Galilean moons, these events can provide their best ground-based
astrometry, with uncertainties in the order of 1 mas ($\sim$ 3 km at Jupiter's
distance during opposition). We organized campaigns and successfully observed a
stellar occultation by Io (JI) in 2021, one by Ganymede (JIII) in 2020, and one
by Europa (JII) in 2019, with stations in North and South America. Also, we
re-analyzed two previously published events, one by Europa in 2016 and another
by Ganymede in 2017. Then, we fit the known 3D shape of the occulting satellite
and determine its center of figure. That resulted in astrometric positions with
uncertainties in the milliarcsecond level. The positions obtained from these
stellar occultations can be used together with dynamical models to ensure
highly accurate orbits of the Galilean moons. These orbits can help plan future
space probes aiming at the Jovian system, such as JUICE by ESA and Europa
Clipper by NASA, and allow more efficient planning of flyby maneuvers.
