This study involves the application of branching fins to pin fin heat sinks with circular bases under natural convection conditions. Branching fins of different fin numbers, pin fin size and spacings, and branching angles are simulated numerically. From the simulation, the thermo-hydraulic flow pattern for different fin spacings is obtained. Further, a parametric study is conducted to investigate the impact of various parameters on the cooling performance, including the number of fins, size and spacing of pin fins, and branching angle. Using branching pin fin heat sinks improves the Nusselt number by around 60% at a reduced mass compared to branching plate fin heat sinks.