The solubility of phenol is 83 g/L, while that of cyclohexanol is 36 g/L. Both of them have a hydroxy group, and can form hydrogen bonds with water. Also, the hydrophobic part of phenol, as well as cyclohexanol is almost the same. Then what is the reason for phenol's better water solubility in water compared to cyclohexanol?
In addition to the acidity difference described in the comments, there is a more subtle effect involving conjugation in the undissociated phenol. When the phenyl group withdraws some electron density from the π-donating hydroxyl group, it gains some negative charge and so is better able to attract the hydrogen ends of the water dipoles. Ultimately this is a manifestation of the polarizability of the delocalized π electrons.