Measurements have been made of the electrical conductivity of sputtered rare‐earth–transition‐metal films. The Wiedemann–Franz law has been used to relate these values to the electronic component of the thermal conductivity of the films. A small lattice contribution to the thermal conductivity was estimated and added to the electronic component to obtain the total thermal conductivity of the materials. This total thermal conductivity is about one order of magnitude smaller than that of the pure bulk materials composing the films. Knowledge of the thermal conductivity of such rare‐earth–transition‐metal films has proved to be useful in the modeling of the thermomagnetic recording processes. These processes are used to record information on magneto‐optic data storage disks.