Surface-activated bonding (SAB) is a direct-bonding method which joins two cleaned surfaces of similar or dissimilar materials at room or low temperature. The practicability and joint quality, however, depend strongly on the smoothness and crystallographic orientation of the bonding surfaces. Supercooled liquid metal possessing high structural homogeneity of the amorphous state and excellent near-net-shape-forming ability may resolve the shortcomings. This work proposes surface-activated supercooled liquid brazing, i.e. a modified SAB technique utilizing supercooled liquid metal as a brazing-filler material.