We describe magneto-optical and magnetic properties of quaternary Cd1−x−yMnxCryTeCd1−x−yMnxCryTe crystals (x=0.37, 0≤y≤0.03)(x=0.37, 0≤y≤0.03) grown by the Bridgman method. The presence of Cr in this alloy is observed to induce ferromagnetic behavior and to enhance magneto-optical effects. Using magnetic circular dichroism and magnetization measurements, we describe the dependence of this behavior on the Cr concentration, and we discuss possible mechanisms for the observed effects.