A tire shape testing device adapted to capture an image of linear light with which a surface of a tire including a sidewall section, a shoulder section, and a tread section has been irradiated and to detect a surface shape of the tire on the basis of the captured image of the linear light, the tire shape testing device comprising: a rotator adapted to hold the tire; first linear light application means adapted to irradiate the tread section of the tire with a linear light beam; second linear light application means adapted to irradiate the sidewall section of the tire with a linear light beam; third linear light application means adapted to irradiate a region comprising at least a part of the shoulder section of the tire and extending to beyond the shoulder section to at least one of a part of the tread section and a part of the sidewall section with a linear light beam; and image capturing means (16,17,18) adapted to capture images of the linear light beams emitted from the first linear light application means, the second linear light application means, and the third linear light application means and reflected by the tire surface; wherein the linear light beams emitted from at least two of the first linear light application means, the second linear light application means, and the third linear light application means overlap on a same line, characterized in that the image capturing means includes first image capturing means and second image capturing means, a first sensor unit including the first image capturing means and the first linear light application means is arranged so as to face the tread section of the tire, a second sensor unit including the second image capturing means, the second linear light application means, and the third linear light application means is arranged so as to face the sidewall section of the tire, and the second image capturing means included in the second sensor unit is configured to capture the image of the linear light beam emitted from the second linear light application means and reflected by the tire surface and the image of the linear light beam emitted from the third linear light application means and reflected by the tire surface. a rotator adapted to hold the tire; first linear light application means adapted to irradiate the tread section of the tire with a linear light beam; second linear light application means adapted to irradiate the sidewall section of the tire with a linear light beam; third linear light application means adapted to irradiate a region comprising at least a part of the shoulder section of the tire and extending to beyond the shoulder section to at least one of a part of the tread section and a part of the sidewall section with a linear light beam; and the image capturing means includes first image capturing means and second image capturing means, a first sensor unit including the first image capturing means and the first linear light application means is arranged so as to face the tread section of the tire, a second sensor unit including the second image capturing means, the second linear light application means, and the third linear light application means is arranged so as to face the sidewall section of the tire, and the second image capturing means included in the second sensor unit is configured to capture the image of the linear light beam emitted from the second linear light application means and reflected by the tire surface and the image of the linear light beam emitted from the third linear light application means and reflected by the tire surface.