In this paper, the effect of hydrophobicity on heat transfer for a flow past an isothermal semicircular cylinder is studied. Hydrophobicity is implemented using the Navier slip model where partial slip is employed on the semicircular cylinder. Here the heat transfer is characterised in terms of local Nusselt number and average nusselt number of the surface. The variation of local Nusselt number at points on the upper surface of the semi-circular cylinder and the average Nusselt number of the entire surface of the body is studied for various slip values and explained. The local Nusselt number follows a trend where Nu decreases from the front stagnation point upto the edges and a local maxima is generated at the edges of the semicircular cylinder (singularity points) and thereafter the Nu minimally increases along the flat surface of the body. When slip is introduced in the body, improvement in Nu is observed along the surface of the semicircular cylinder except at the singularity point which is located at the edge of the body. The average Nusselt number \(\overline{Nu}\) of the isothermal body increases with introduction of slip and becomes higher for higher values of slip length and Reynolds number of the fluid.