The casting process is used to manufacture gas turbine blades and their internal cooling passages. Jet impingement cooling is used to cool the gas turbine blade. During the casting process, the shape of the orifice may get distorted, affecting the heat transfer rate. Therefore, it is necessary to study the effect of the shapes of the orifices on the heat transfer rate. The present study investigates four different shapes, i.e., circular, elliptical, triangular, and square. The equivalent diameter of all the orifices is maintained the same, i.e., 6 mm. The equivalent diameter is employed to calculate the Reynolds number. In this study, the distance between the jet and the plate (z/d) is chosen to be from 1 to 5. This study includes the Reynolds number ranging from 5000 to 20000. Except at z/d = 4, the effect of the shapes of the orifice on the heat transfer rate is not observed. At z/d = 4, a non-circular orifice has a higher heat transfer rate than a circular one.