Sludge (disambiguation)

Sludge is a semi-solid slurry produced from industrial processes.

Sludge may also refer to:
 * Sewage sludge
 * Mining sludge
 * Biliary sludge
 * Oil sludge, a solid or gel in motor oil caused by the oil gelling or solidifying
 * Sludge metal, a fusion genre between doom metal and hardcore punk
 * Sludge content, a split video format
 * Sludge (comics), an Ultraverse comic book
 * Sludge (film), a 2005 documentary film by Appalshop filmmaker Robert Salyer
 * SLUDGE syndrome, a medical acronym describing the symptoms of overdose or poisoning of certain drugs and pesticides
 * Sludge (news), an investigative journalism news outlet covering lobbying and money in politics
 * Sludge theory, an economic behavioral theory