Liquefaction may refer to:

• Soil liquefaction, the process by which sediments are converted into suspension, as in earthquake liquefaction, quicksand, quick clay, and turbidity currents
• Liquefaction of gases in physics, chemistry, and thermal engineering
• Liquification, the process of making or becoming liquid (a more general term, sometimes used in place of liquefaction in the energy industry, food processing, and also in sperm maturation)