A coated cutting tool comprising: a substrate; and a coating layer formed on a surface of the substrate, wherein: the coating layer comprises a lower layer, an intermediate layer and an upper layer in this order from the substrate side; the lower layer comprises one or more Ti compound layers containing a Ti compound of Ti and an element of at least one kind selected from the group consisting of C, N, O and B; and the intermediate layer comprises an α-Al2O3 layer containing α-Al2O3; and the upper layer comprises a TiCN layer containing TiCN; an average thickness of the coating layer is within a specific range, and an average thickness of the upper layer is within a specific range; in a cross section perpendicular to the surface of the substrate, the grains in the TiCN layer constituting the upper layer satisfies a specific condition.