A shape measurement method for a tire includes: detecting an outer surface shape data and an inner surface shape of the tire from image data of the outer surface and the inner surface; subjecting irregularities along the tire circumferential direction around the tire in the outer surface shape data and in the inner surface shape data to Fourier transformation to take out primary waveform components respectively; adjusting the tire circumferential positions of both of the waveform components to adjust the tire circumferential positions thereof; adjusting the tire radial direction cross section positions of the outer surface shape data and the inner surface shape data from information about the placement angles and the positions of the first camera and the second camera; and synthesizing the outer surface shape data and the inner surface shape data based on the adjusted tire circumferential positions and the tire radial direction cross section positions.