Heat sink paste or thermal paste is a chemical compound which is commonly used as an interface between heat sinks and heat sources such as high-power semiconductor devices. The main role of thermal paste is to eliminate air gaps or spaces from the interface area between the electronic component and the heat sink in order to maximize heat transfer and dissipation.

Thermal paste is also referred to as thermal compound, thermal grease, thermal interface material, thermal gel, heat paste, heat sink compound, heat sink paste or CPU grease.