Publisher Summary This chapter provides an overview on microwave welding. Microwave welding is a type of electromagnetic welding that uses high electromagnetic radiation to heat a susceptor material located at the joint interface. Heat generation occurs in microwave welding through absorption of microwave energy by susceptor materials that contain polar groups as part of their molecular structure or that are electrically conductive. In an applied electric field, polar groups align in the field direction. In a microwave, the magnitude and direction of the electric field changes rapidly; polar molecules develop strong oscillations as they continually align with the field, generating heat through friction. The chapter also highlights the advantages and disadvantages associated with microwave welding.