High entropy alloys (HEAs) are remarkable engineering materials with a unique structural design and diverse properties, making them widely applicable. This review focuses on their utilization in interfacial joining, offering a systematic summary of their wetting characteristics as both filler alloys and substrates. The wetting and brazing behavior of HEAs in interfacial joining are examined for both filler alloys and substrates. The review also addresses current research limitations and outlines future perspectives for HEAs in interfacial joining applications. This research lays the groundwork for further advancements in the field.