A vacuum truck or vacuum tanker is a tanker truck that has a pump and tank. This pump is designed to pneumatically suck liquids, sludge, slurries, etc. from a location (usually underground) into the tank of a truck. The aim is to enable the liquid material to be transported by road to another location. The vacuum truck transports the collected material to a treatment or disposal site, such as a sewage treatment plant.

A common material transported by Vacuum trucks is septic, which is human waste mixed with water, for example, from septic tanks and pit toilets. They also use pens to transport sewage sludge, industrial liquids, or slurries from animal manure from livestock facilities. Vacuum trucks can also be used to prepare installation sites or access underground utilities. Before starting installation, these trucks may use compressed air or water to break the ground safely without risk of damage. If the Vacuum truck is used to remove sand from sewers, it can be equipped with a high pressure pump.

Vacuum trucks serve several types of decentralised sanitary systems. They are used for emptying septic waste from cesspits, septic tanks, pit latrines, and public toilets, for street cleanup, for sewer cleanup, and for individual septic systems. Trucks are used to clean sewer pumping stations. Vacuum trucks are used to empty portable toilets. In commercial aviation, Vacuum trucks can be used to collect waste from aircraft toilets.