The optical reflectivity at 300 K in magnetoplumbite PbFe12O19 was measured at photon energies up to 30 eV using synchrotron radiation spectroscopy. The sample surface was a natural face perpendicular to the crystalline c axis. The crystal was prepared by the flux evaporation technique. By means of the Kramers–Kronig analysis and with the aid of the previous reflectivity and ellipsometry results, the spectra of the complex permittivity ε, the optical constants n and k, the absorption coefficient, and −Im ε−1 were obtained in the spectral range from 2 to 29 eV. At the photon energies below 10 eV the reflectivity spectrum of PbFe12O19 shows a strong analogy with that of lithium ferrite Li0.5Fe2.5O4. This may be due to the fact that the magnetoplumbite unit cell contains the spinel blocks. At photon energies above 10 eV the amplitudes of maxima of the two compounds differ significantly: the peak centered near 18.5 eV observed in the magnetoplumbite reflectivity spectrum is much stronger than the corresponding structure in lithium ferrite. This is consistent with the higher refractive index in magnetoplumbite at the low-energy end of the spectrum.