A systematic study of Y III atomic properties is carried out using high-precision relativistic all-order method. Recommended values and estimates of their uncertainties are provided for a large number of electric-dipole reduced matrix elements, transition rates, and oscillator strengths for allowed transitions between ns, np(j), nd(j), nf(j), and ng(j) levels with n <= 8. The lifetimes of these levels are also evaluated. Electric-quadrupole and magnetic-dipole matrix elements are calculated to determine lifetimes of the 4d(5/2) and 5s metastable levels. The ground-state E1, E2, and E3 static polarizabilities are calculated. This work provides recommended values critically evaluated for their accuracy for a number of Y III atomic properties for use in theoretical modeling as well as planning and analysis of various experiments. We hope that the present study will stimulate further exploration of Y III for various applications owing to its interesting structure of different low-lying metastable levels. DOI: 10.1103/PhysRevA.87.032501