Titanium monoxide with the basis crystal structure B1 is of interest because of an anomalously high concentration of vacancies and diverse effects of atom-vacancy ordering. It was previously believed that the application of relatively low pressures to such systems does not change the crystal structure type, and the crystal structure is densified through a decrease in the equilibrium concentration of defects. The genetic algorithm to search for optimal structures and calculations by the electron density functional method have demonstrated that phases with a structure derivative of the B1 structure should be metastable in a wide pressure range from 0 to 100 GPa. Two defectless hexagonal modifications—the ɛ-TiO and H-TiO phases—are thermodynamically stable at P < 28 GPa and P > 28 GPa, respectively. These phases demonstrate a pronounced pseudogap at the Fermi level and, thereby, have a low electrical conductivity.