From the orientational dependence of the quadrupole energies, it is assumed that hydrogen molecules can take only four orientations characterized by the symmetry axis pointing to the [111] direction in the face-centered cubic lattice. It is shown that solid ortho-hydrogen undergoes the first-order phase transition for the molecular orientations. The transition temperature is derived in the mean-field approximation, and reexamined by means of the computer simulation. The intensity of x-ray diffuse scattering caused by orientational disorder shows an anomalous behavior at the transition temperature.