Ionic liquids have been considered as "green" replacements for volatile organic compounds in modern and clean industrial processes since the beginning of the 1990s. It has been shown recently that when combined with renewable feedstocks derived from biomass (like carbohydrates) they form systems attractive for sustainable chemical engineering and technology. Promising features of such systems have induced research activity in various areas of pure and applied chemistry. In particular, new experimental data on different thermodynamic properties of biomaterials dissolved in ionic liquids are required. In this paper we present both experimental and theoretical thermodynamic studies of binary mixtures composed of sugars and two low-viscous ionic liquids based on 1-butyl-3-methylimidazolium cation and dicyanamide or trifluoroacetate anion. Solubility of D-(+)-glucose, D-(-)-fructose, and sucrose in the ionic liquids was determined as a function of temperature. The results indicate that both ionic liquids under consideration can be successfully applied as alternative solvents for sugars. Additionally, thermal characterization of pure sugars was performed with differential scanning calorimetry. The obtained solid-liquid equilibrium phase diagrams were analyzed in terms of perturbed-chain statistical associating fluid theory (PC-SAFT). It was shown that the PC-SAFT model is capable of representing phase behavior of the studied systems quantitatively.