Flux-cored arc welding (FCAW) is a semi-automatic or automatic arc welding process. FCAW requires a continuously-fed consumable tubular electrode containing a flux and a constant voltage or, less commonly, a constant electric current welding power supply. An externally supplied shielding gas is sometimes used, but often the flux itself is relied upon to generate the necessary protection from the atmosphere. The process is widely used in construction because of its high welding speed and portability.

FCAW was first developed in the early 1950's as an alternative to shielded metal arc welding (SMAW). The advantage of FCAW vs. SMAW is that the use of stick electrodes (like those used in SMAW) was unnecessary. This helped FCAW to overcome many of the restrictions associated with SMAW.