Slag is a by-product of smelting ore.
Slag may also refer to:
Arts, entertainment, and media Slag (play), an early play by David Hare Slag (video game), a 1980 game for the TRS-80 Slag (Transformers), a fictional character in the Transformers series The Slag brothers, characters in the American animated television series Wacky Races
Other uses Slag (welding), a by-product of some arc welding processes Slag, a pejorative British term for slut Slag, an alternative name for spoil tip, mining waste
See also "Slag off" (Irish), see Insult comedy