A rotor blade of a wind turbine, wherein the rotor blade has in particular a splitter plate, which is arranged on the blunt trailing edge of the rotor blade. The splitter plate comprises: a root edge, wherein the root edge is arranged on, in particular along, the trailing edge below a transition from the suction side into the trailing edge, an end edge, wherein the end edge forms a free edge, and a surface between the root edge and the end edge, wherein the surface has at least one curved part between the root edge and the end edge, and at least one part of the surface lies in the shear layer generated by the suction side. A rotor blade of a wind turbine, wherein the rotor blade has in particular a splitter plate, which is arranged on the blunt trailing edge of the rotor blade. The splitter plate comprises: a root edge, wherein the root edge is arranged on, in particular along, the trailing edge below a transition from the suction side into the trailing edge, an end edge, wherein the end edge forms a free edge, and a surface between the root edge and the end edge, wherein the surface has at least one curved part between the root edge and the end edge, and at least one part of the surface lies in the shear layer generated by the suction side.