It was originally named for Isaac Ingalls Stevens, then renamed for Charles Thomas Stearns.

The Stearns County area was formerly occupied by numerous indigenous tribes, such as the Sioux (Dakota), Chippewa (Ojibwe) and Winnebago (Ho-chunk).

It was to be named Stevens County for territorial governor Isaac Ingalls Stevens, who had conducted an expedition through the area in 1853, but due to a clerical error, the county was named Stearns for Charles Thomas Stearns, a member of the Territorial Council.

Writing in 1997, Jewish-American historian of America's religious architecture Marilyn J. Chiat commented, "Father Francis X. Pierz, a missionary to Indians in central Minnesota, published a series of articles in 1851 in German Catholic newspapers advocating Catholic settlement in central Minnesota.

Stearns County retains in its German character and is still home to one of the largest rural Catholic populations in Anglo-America.

In 1913 a campaign was mounted to shift the county seat to Albany, due to its more central location.

The county terrain consists of low rolling hills, lightly wooded, dotted with lakes and ponds, and carved with drainages.

The land consists of rolling hills, scenic lakes, prairies, savannas and woodlands of a mixture of coniferous and deciduous trees.

In its early history Stearns County was heavily Democratic due to being largely German Catholic and opposed to the pietistic Scandinavian Lutheran Republican Party of that era.

[19] Anti-Woodrow Wilson feeling from World War I caused the county to shift overwhelmingly to Warren G. Harding in 1920 before swinging to Robert M. La Follette, coreligionist Al Smith and fellow “wet” Democrat Franklin D. Roosevelt.

In 1936 the county's isolationism gave strong support to William Lemke’s Union Party.

Since the “Reagan Revolution”, Stearns County has voted reliably Republican, with no Democrat gaining a majority since Jimmy Carter in 1976, and Bill Clinton in 1996 the only one to manage a plurality.

The county's growing social conservative bent has fueled the Republican trend.

In 2016 Donald Trump won the county with 59.8% of the vote, the highest percentage any presidential candidate has received since President Eisenhower in 1956.