Sanitary engineering is the application of engineering methods to improve sanitation of human communities, primarily by providing the removal and disposal of human waste, and in addition to the supply of safe potable water. Initially in the mid 19th century, the discipline concentrated on the reduction of disease, then thought to be caused by miasma. This was accomplished mainly by the collection and segregation of sewerage flow in London specifically, and Great Britain generally. These and later regulatory improvements were reported in the United States as early as 1865.

It is not concerned with environmental factors that do not have an immediate and clearly understood effect on public health. Areas outside the purview of sanitary engineering include traffic management, concerns about noise pollution or light pollution, aesthetic concerns such as landscaping, and environmental conservation as it pertains to plants and animals.

Skills within this field are usually employed for the primary goal of disease prevention within human beings by assuring a supply of healthy drinking water, removing garbage from inhabited areas, and so on.