Love numbers describe the fluid and elastic response of a body to the tidal force of another massive object. By quantifying these numbers, we can more accurately model the interiors of the celestial objects concerned. We determine Saturn's degree-2 Love number, $k_2$, at four different tidal forcing frequencies. To do this, we used astrometric data from the Cassini spacecraft and a dynamical model of the orbits of Saturn's moons. The values obtained for $k_2$ are $0.384 0.006$, and 0.376 $ 0.007$ (1 sigma error bar) for the tidal frequencies of Janus--Epimetheus, Mimas, Tethys, and Dione. We show that these values are compatible with a constant Love number formulation.
In addition, we compared the observed values with models of dynamical tides excited in Saturn's interior, also finding a good agreement. Future increases in the measurement precision of Love numbers will provide new constraints on the internal structure of Saturn.