The county is named in honor of Homer E. Sargent, a 19th-century general manager of the Northern Pacific Railroad Company.

[3] It is the 29th-most populous county in North Dakota, and was the original home of the Bobcat Company, a manufacturer of farm and construction equipment that still produces a large number of skid-steer loaders at its facility in Gwinner.

The county's population rapidly increased, reaching a peak in the 1920 United States census (9,655).

[4] In 1997 the Brampton Lutheran Church (originally built in 1908) was moved to Sletta near Radøy in Norway and reconstructed there.

The Sargent County Courthouse, a Beaux Arts-style building built in 1910, is listed on the U.S. National Register of Historic Places.

The flatter areas of the county are largely devoted to the production of corn, soybean, and wheat, with much of the more hilly terrain being used as pastures for grazing livestock.

[8] The terrain generally slopes to the south and east, with its highest point on its western boundary line at 1,365 ft (416 m) ASL, although a northwest–southeast rise on the eastern portion of its south boundary line rises to 1,729 ft (527 m) ASL.

[9] Sargent County is located within the Prairie Pothole Region of the northern Great Plains, and as such has a landscape that is covered in numerous wetlands.

The majority of these wetlands are shallow sloughs that vary in size in wetter and drier years, but there are also a number of larger and deeper lakes.