We report the first observation of Faraday rotation of light in multiple-scattering media. Speckle patterns generated by diffusive transport of laser light through turbid granular samples are strongly modified by high magnetic fields (B). The speckle intensity correlation function, measured at various sample thicknesses and Verdet constants, decays with increasing B in agreement with the simple model discussed. In addition the coherent backscattering cone is partially suppressed by the field, again consistent with the model. This effect provides a unique way to destroy interferences between time-reversed scattering paths and may be expected to affect light localization.