Air-pollutant transport is the advection or horizontal convection of air pollutants from an area where emission occurs to a downwind receptor area by local or regional winds. It is sometimes referred to as atmospheric transport of air pollutants. This movement of air pollution is often simulated with computer models for point sources as well as for large diffuse sources such as urban regions.

In some cases, strong regional winds or low-level nocturnal jets can carry pollutants hundreds of miles from source areas of high emissions. The possibility of transport over such distances can be increased through topographic channeling of winds through valleys. Air-pollutant transport over such distances is often referred to as long-range transport.

Air-pollutant transport is an important consideration in air quality planning. Where such impact occurs, the success of an air quality program may depend on the ability of air pollution control agencies to control upwind sources.