Microspheres possess high quality factor morphology-dependent resonances, i.e., whispering gallery modes. Additionally, silicon is proving itself to be an excellent optical material. We have studied the feasibility of silicon microspheres as a optical filters at THz communication frequencies. The silicon microsphere has a radius of 500 μm and a refractive index of 3.4. Elastic scattering spectra are calculated for TE and TM polarizations for wavelengths between 90 μm and 100 μm in the THz communication band. The high quality factor morphology dependent resonances are found to have a repetitive mode spacing of 1.2 μm.