Salt tolerance, in a single definition, refers to an organism's ability to survive and reproduce under conditions of high salt concentrations in the soil or water, without showing any significant negative effects on growth or development. This adaptation allows plants, animals, and microorganisms to thrive in saline environments, where non-halotolerant species would typically struggle or die due to ion toxicity, osmotic stress, and nutritional imbalances. Salt tolerance is a crucial trait for organisms living in coastal areas, salt marshes, deserts, and other habitats with high salinity levels.

'Salttåliga växter' är växter som kan tolerera och fortsätta att gro, växa och fortplanta sig under högre nivåer av saltkoncentration i marken eller i vattnet än vanligt, tack vare speciella anpassningar i deras fysiologi och metabolism.