Photoluminescence (PL) of Lu2SiO5 crystal and ceramics with a high concentration of oxygen vacancies (0.1-0.5 at.%) is studied. Oxygen vacancies were created using two ways. The first method is a growth of crystal from the non-stoichiometric Lu2Si0.98O4.96 melt and the second one is a doping of Lu2SiO5 matrix with divalent Ca2+ ions at the concentration of 1 at.%. For the first time we observe a fairly bright room-temperature ultraviolet PL of both crystal grown from the Lu2Si0.98O4.96 melt with the composition Lu2Si0.996O4.992 and Lu2SiO5 ceramics doped with Ca2+ ions. A band at 290 nm in the PL spectrum of the crystal and a band at 283 nm in the PL spectrum of the calcium-doped ceramics are observed. The spectral and kinetic properties of these bands are close to each other. This fact indicates similar origins of these bands. The results of the work show that the studied ultraviolet luminescence is related to oxygen vacancies in lutetium oxyorthosilicate •Bright luminescence from oxygen-deficient Lu2SiO5 at room-temperature is observed.•Emission at 280-290 nm is dipole-resolved and due to oxygen vacancies.•Parameters of the emission are close to STE luminescence from Lu2SiO5.