The B-site ordered double perovskite Sr₂CaOsO₆ has been synthesized by a solid-state reaction under ambient pressure. Sr₂CaOsO₆ is isostructural to Sr₂NaOsO₆ and Sr₂CaReO₆, thus crystallizes in the monoclinic space group P2₁/n, in contrast to cubic lattice symmetry reported in an earlier publication. The compound remains paramagnetic down to a temperature of 2 K. This finding is of relevance with regard to the high-temperature ferromagnetism observed in Sr₃OsO₆ thin films and may find interest in view of possible exotic ground states in frustrated magnetic systems.