Solubility data for the reciprocal system Ca2+, Mn2+//F-, SO42- + H2O is very important for the removal of fluoride or calcium ions from the MnSO4 aqueous solution by CaF2(s) precipitation; however, these data have not been reported in literature to date. In this work, the solubility data for the ternary systems CaF2 + MnSO4 + H2O, CaF2 + MnF2 + H2O, and MnF2 + MnSO4 + H2O and the quaternary systems CaF2 + CaSO4 + MnSO4 + H2O and CaF2 + MnF2 + MnSO4 + H2O were measured in detail at 298.15 K. The results showed that CaF2(s) solubility increases monotonically with increasing MnSO4 concentration in the CaF2 + MnSO4 + H2O system, and MnSO4 produces a stronger salting-in effect on CaF2(s) than ZnSO4. CaF2(s) solubility decreases with the increase in the MnF2 concentration and increases again after reaching the minimum value. In the MnF2 + MnSO4 + H2O system, the addition of MnSO4 results first in a decrease and then in an increase of the MnF2(s) solubility, similar to the MgF2(s) solubility behavior in the MgF2 + MgSO4 + H2O system. In the CaSO4 center dot 2H(2)O((s))-saturated solution, CaF2(s) solubility increases with increasing MnSO4 concentration but is generally lower than that in the pure MnSO4 aqueous solution. In the MnF2(s)-saturated solution, CaF2(s) solubility increases with increasing MnSO4 concentration but is remarkably lower than that in the pure MnSO4 aqueous solution. The reciprocal system Ca2+, Mn2+//F-, SO42- + H2O exhibits cosaturated phase fields of CaSO4 center dot 2H(2)O((s))- CaF2(s)-MnSO4 center dot H2O(s), CaF2(s)-MnSO4 center dot H2O(s), and CaF2(s)-MnSO4 center dot H2O(s).