A magnetic block toy includes: a block body having, on outer surfaces thereof, coupling sections and non-coupling sections; and disk magnets provided inside the coupling sections in the block body. The block body includes magnet-holding portions where the disk magnets are arranged along the coupling sections and held in a circumferentially rotatable manner. Length of at least one side of the block body is equal to or longer than 30 millimeters and shorter than 40 millimeters. Only the coupling sections are provided with labels indicative of being capable of coupling to a coupling target. In the coupling sections, stepped portions are formed so that at least part of an outer-edge portion of each coupling section protrudes.