The shear difference method is developed here for application to orthotropic photoelasticity problems. The two-dimensional stress-optic law which was presented in another paper is used. The stress-optic law provides two equations for the three plane stress components and the shear difference method may be used to obtain the third relation. This paper presents the development of the general orthotropic shear difference method for any material orientation. For orientations aligned with the material principal directions, the relations are identical to the isotropic shear difference method. The solution of an orthotropic tensile strip with a central hole demonstrates application of the orthotropic shear difference method and further confirms the orthotropic stress-optic law. Good agreement was found between the photoelastic and theoretical solutions.