This article presents a review of the applications incorporating waste heat recovery (WHR) and phase change materials (PCM). PCM can provide stability to WHR systems by smoothing the output power and contributing to peak shavings. The current study also compares the utilization of PCM and sensible storage in which the former can increase the heat storage capacity and decrease the total energy consumption. Different WHR sources were investigated: industry, internal combustion engine, solar-based system, heating, air conditioning, and adiabatic compressed air energy storage. Several enhancements to PCM are discussed and especially the nano-enhanced and composite PCM.