Microwave Hall‐effect measurements have proven invaluable for determining the Hall mobility in a wide variety of both organic and inorganic materials. Since some of these materials crystallize into needle shapes, the question of depolarization effects and the measurement and interpretation of the cavity‐scattering parameters describing the microwave Hall effect have yet to be addressed. It will be shown in this paper that the microwave Hall mobility can be found under any polarization conditions by direct measurement of the cavity input and output reflection coefficients, as well as the cavity transmission factor. Experimental results supporting this premise are presented. In addition, the sign of the microwave Hall mobility is shown to be a function of the degree of sample polarization.