In this letter, we investigate the outage probability (OP) performance of a multirelay multiuser hybrid satellite-terrestrial relay network operating at millimeter wave (mmWave) bands. Considering the dominant fading factor of the mmWave band is rain attenuation, we combine the long-term rain attenuation model with the statistical channel model to describe the mmWave channel. Then we utilize expected rain attenuation value of satellite links to select the desired relay node to improve the OP performance of the considered system, and the exact closed-form expressions of OP for both variable and fixed gain relaying protocols are derived. Finally, numerical and simulation results are provided to validate our analytical results.