Donaldson Company, Inc. is a filtration company engaged in the production and marketing of air filters used in a variety of industry sectors, including commercial/industrial (engines, exhausts, transmissions, vents in private vehicles, hydraulics), aerospace (helicopters, planes), chemical, alternative energy (windmills) and pharmaceuticals.

As a multinational company it operates in Belgium, Mexico, China, UK, Czech Republic, Malaysia, Thailand, USA, South Africa, Russia,[4] Japan, Italy, Germany and France.

The company has been recognized for innovations made in air filter technology (since 2008 annual spending on research and development has exceeded $40.6 million).

Its focus mainly being on advanced development of modularized, collective protection for military vehicles, vans and shelters,[9] nuclear, biological and chemical protection, development of CBRN defense systems (primarily for detection and warning of chemically contaminated environment, air and/or surface decontamination equipment,) for combat vehicles and manpower in the field, intended for use with all military branches of the United States Armed Forces,[10] air filtration systems for missile systems and space vehicles,[11] M1 Abrams main battle tank turbine engines,[12] and complex military equipment such as the AN/TPQ-36 and AN/TPQ-37 Firefinder radars.

[13] Donaldson-developed chemical defensive material includes protective clothing and equipment to secure area and enclosures/compartments from chemical contamination, protect military personnel and individual soldiers from chemical agents; collective protection shelters for certain military headquarters and military communications functions, for rest and relief, and for certain vehicle crews; manual and automatic detection and warning devices that respond to toxic agents on all surfaces, in the atmosphere, and in food and water; means to decontaminate skin, clothing, equipment, terrain, food, and water.

The 1930’s were a transitional period, beginning with tough economic conditions in the United States which caused business from farmers to fall and subsequently forcing the company to contract in size.

World War II provided opportunities for the company to expand into aerospace and military hydraulic equipment and device filters.