We investigated the features of the optical properties of magnetoactive cholesteric liquid crystals (CLCs) in an external static magnetic field. The boundary-value problem of light transmission through a finite layer of a magnetoactive CLC at normal light incidence and light reflection from a half-space is considered. We also investigated the evolution of the reflection with a change in the azimuth and ellipticity of the incident light. Some features of the reflection spectra, optical rotation, and polarization ellipticity, as well as the ellipticity spectrum of the eigen polarizations, are investigated, too. The peculiarities of the ellipticity evolution of the eigen polarizations due to a change in the magneto-optical activity parameter are considered.