The Hansen solubility parameters (HSPs) of some ionic liquids with different combinations of cations and anions were measured and calculated. The Hansen solubility sphere method was used to calculate the HSPs of ionic liquids from experimental data on the solubility evaluation of the ionic liquids in some organic solvents. It was found that the double-sphere method rather than the general single-sphere method was suitable for this evaluation. For double-sphere analysis, the high polarity side sphere represents an ionic domain and the nonpolar side sphere represents a neutral domain. The value as the center of each sphere was assumed to be the HSP for each domain. The calculation results confirmed that the positions of the double-sphere in Hansen’s 3D-diagram for the ionic liquid depended on the types of cation and anion.