In this work, manganese whitlockite (Mn-WH, Ca18Mn2(HPO4)2(PO4)12) was successfully synthesized and comprehensively characterized. This material is a manganese-containing analog of the biomineral magnesium whitlockite (Mg-WH, Ca18Mg2(HPO4)2(PO4)12). The synthesis was performed via a low-temperature dissolution-precipitation process in aqueous medium under ambient pressure at 75 °C using dicalcium phosphate dehydrate and manganese acetate tetrahydrate as starting materials. The crystal structure of the synthesized powder was determined by powder X-ray diffraction, FTIR and Raman spectroscopies, demonstrating the presence of characteristic structural units. Morphological features and elemental distribution within the synthesized powder were studied by SEM/EDX analysis. XPS, EPR and magnetic studies confirmed the presence of Mn ions in a divalent state. Temperature-dependent magnetic measurements revealed a paramagnetic behavior of Mn-WH down to 5 K. In vitro cytotoxicity experiments were performed with MC3T3-E1 preosteoblastic cell line.