Partition coefficients for phenol; o-, m-, and p-cresols; 3,5-xylenol; and alpha-naphthol in an ionic liquid/water two-phase system were measured at 298.2 K. 1-Butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) was used as the ionic liquid. Further, the infinite dilution partition coefficients were also determined by extrapolation. The infinite dilution partition coefficients were correlated by regular solution theory. Interaction parameters between phenolic compounds and [bmim][PF6] pairs were determined by plotting the infinite dilution partition coefficients against the solubility parameters of the phenolic compounds. The correlated results are in good agreement with the experimental data.