Highly refractive poly(phosphonate)s (BPOP), poly(thiophosphonate)s (BPTP), and poly(selenophosphonate)s (BPSP) with aromatic backbones were prepared by the polycondensation of phosphonic dichlorides and diols. The polymers have high thermal properties including high thermal properties (Td5% > 400 °C), glass transition temperature (Tg = 76 ~ 157 °C), and high optical properties such as transparency at 400 nm of over 80% for films of ca. 10 μm thickness, and a refractive index in the range of 1.633–1.675. In particular, BPSP exhibited a high refractive index (1.675) with low birefringence (0.0025) due to the heavy atom effect of selenium.Graphical abstractThis paper represent synthesis and characterization of highly refractive and transparent poly(phosphonate)s (BPOP), poly(thiophosphonate)s (BPTP), and poly(selenophosphonate)s (BPSP) with aromatic backbones in the polymer chains. The poly(phosphonate)s was prepared by the polycondensation of phosphonic dichlorides and diols. The polymers exhibited high thermal properties such as glass transition temperature (> 76 °C), and 5% weight loss temperature at > 393 °C under nitrogen. The polymers also showed good optical properties, including high optical transparency in the visible region, a low birefringence of 0.0099–0.0026, and high refractive indices of 1.6333–1.6757 at 637 nm.