The solubility data of gliclazide in 10 mono-solvents (1,2-dichloroethane, 1,4-dioxane, 2-methoxyethanol, n -propyl acetate, isopropyl acetate, n -butyl acetate, pentyl acetate, dimethyl sulfoxide (DMSO), N , N -dimethylacetamide (DMA), and 2-butanone) and one kind of binary solvent (DMA + water) were measured between 278.15 and 323.15 K under atmospheric pressure by the gravimetric method. The Hansen solubility parameters and the KAT-LSER equation were used to investigate the solubility order and the influence of solvent effects on solubility. The experimental data were correlated by six thermodynamic models (the λ h model, the Yaws model, the Apelblat model, the Jouyban model, the modified Jouyban-Acree model, and the Sun model). The results show that all of these models can correlate the experimental data well. Among them, the Apelblat model is the most suitable for correlating the solubility data of gliclazide in mono-solvents and binary solvents.