Solid-liquid equilibrium data were measured for binary and ternary mixtures composed of diphenylmethane with closely boiling compounds: 2-methoxyphenol (or guaiacol, CAS [90-05-1]) and 1,2-dimethoxybenzene (or veratrole, CAS [91-16-7]). Experimental results revealed that all the binaries behave as simple eutectic systems. The eutectic loci were also observed for the mixtures of diphenylmethane + 2-methoxyphenol + 1,2-dimethoxybenzene, from which a ternary solid-liquid equilibrium phase diagram was obtained. A feasible separation sequence, on the basis of the phase diagram, was then proposed to separate the mixture of 2-methoxyphenol and 1,2-dimethoxybenzene by means of extractive crystallization with diphenylmethane as an entrainer. The Wilson and the NRTL models were employed to correlate the equilibrium data of binary systems. These two models with the determined parameters predicted the solid-disappearance temperatures of the ternary system to grand average absolute deviations of better than 0.43%.