The two dimensional Kemmer oscillator under the influence of the gravitational field produced by a topology such as the cosmic string spacetime and in the presence of a uniform magnetic field as well as without magnetic field are investigated. The eigensolutions of our problem have been found by using the generalized parametric Nikiforov–Uvarov (NU) method, and the influence of the cosmic string space-time on the energy spectrum has been analyzed. We show that the dependence of the energy levels of the quantum system with the angular deficit \(\alpha\), which characterizes the global structure of the metric in the cosmic string spacetime, breaks the degeneracy of these levels.