In the title compound, C(16)H(15)N(3)O(2)·H(2)O, the mean plane of the approximately planar pyrazole ring [maximum deviation = 0.0474 (18) Å] makes dihedral angles of 86.32 (11) and 45.04 (10)° with the phenyl and pyridine rings, respectively. The dihedral angle between the phenyl and pyridine rings is 69.62 (11)°. In the crystal, inter-molecular O-H⋯O and O-H⋯N hydrogen bonds connect the components into chains along [010]. The crystal structure is further stabilized by π-π stacking inter-actions with centroid-centroid distances of 3.7730 (12) Å.