Perovskite-structured solid solutions intended for use as microwave dielectric resonators were studied by Raman spectroscopy. Two distinct categories were investigated: (i) simple perovskite–simple perovskite solid solutions, that is, CaTiO3–SrTiO3 (CTST), CaTiO3–CaZrO3 (CTCZ), CaTiO3–NdAlO3 (CTNA), and CaTiO3–LaGaO3 (CTLG); and (ii) simple perovskite–complex perovskite solid solutions, such as CaTiO3–SrMg1/3Nb2/3O3 (CTSMN). In the latter category, the influence of A-site ion radius was also addressed by examining 0.5CaTiO3– 0.5LaMg1/2Ti1/2O3 (0.5CT–0.5LMT), 0.5SrTiO3 (ST)–0.5LMT, and 0.5BaTiO3 (BT)–0.5LMT. Raman data from the end members and solid solutions are compared, paying particular attention to F2g and A1g mode bands, often associated with ordering of B-site species.