The Kamlet–Taft solvent parameters of solvate ionic liquids (SILs) prepared from lithium salts with glyme and glycol ligands are determined. The dipolarity/polarisibilities (π*) are high, similar to those found in conventional ionic liquids. The H-bond basicities (β) depend strongly on the anion. The H-bond acidities (α) are high in both glyme and glycol SILs, indicating that the lithium is acting as a H-bond donor site. “Poor” SILs have glyme-rich and salt-rich regions. In these liquids the π* and β values are almost identical to the parent glyme or glycol, and the α values are determined by the salt alone.