Dumpster diving (also totting, skipping, skip diving or skip salvage) is salvaging from large commercial, residential, industrial and construction containers for unused items discarded by their owners but deemed useful to the picker. It is not confined to dumpsters and skips specifically and may cover standard household waste containers, curb sides, landfills or small dumps.

Different terms are used to refer to different forms of this activity. For picking materials from the curbside trash collection, expressions such as curb shopping, trash picking or street scavenging are sometimes used. In the UK, if someone is primarily seeking recyclable metal, they are scrapping, and if they are picking the leftover food from farming left in the fields, they are gleaning.

People dumpster dive for items such as clothing, furniture, food, and similar items in good working condition. Some people do this out of necessity due to poverty, others do it for ideological reasons or professionally and systematically for profit.