Provided, as a transparent magneto-optical material which does not absorb fiber laser light within a wavelength range of 0.9-1.1 μm and is thus suitable for constituting a magneto-optical device such as an optical isolator wherein the formation of a thermal lens is suppressed, is a magneto-optical material which is composed of a transparent ceramic that contains a complex oxide represented by formula (1) as a main component, or which is composed of a single crystal of a complex oxide represented by formula (1). Tb2xR2(2-x)O8-x  (1) (In the formula, 0.800