The isobaric vapor-liquid equilibrium (VLE) data for the binary systems 2-methoxyethanol + ethylbenzene, ethylbenzene + dimethyl sulfoxide (DMSO), and 2-methoxyethanol + DMSO and the ternary system 2-methoxyethanol + ethylbenzene + DMSO were measured with a Fischer VLE 602 apparatus at 100.00 kPa. The VLE data for all the binary and ternary systems were thermodynamically consistent and passed the Wisniak's L-W test. The binary VLE data were correlated with the Wilson, nonrandom two-liquid, and universal quasichemical models with minor deviations. The ternary VLE data predicted from the corresponding binary interaction parameters agreed well with the experimental data. The azeotropic temperature and composition of the 2-methoxyethanol and ethylbenzene azeotropic mixture at 100.00 kPa were 391.05 K and 60.15 mol % 2-methoxyethanol, respectively. Additionally, the azeotrope disappeared after adding DMSO, which confirms that DMSO can serve as a prospective entrainer for separating 2-methoxyethanol from ethylbenzene in the extractive distillation process.