Morrison County is a county in the U.S. state of Minnesota. As of the 2020 census, the population was 34,010. Its county seat is Little Falls. Camp Ripley Military Reservation occupies a significant area in north-central Morrison County.

Dakotah and Ojibwe Indians lived in central Minnesota around the Mississippi River. French and English fur traders and voyageurs traveled through Minnesota from the 17th century to the 19th century. They used the river to transport their goods and trade with the natives. The county was named for fur trading brothers William and Allan Morrison.

In the 19th century three prominent explorers led expeditions along the river through the area that became Morrison County. Zebulon Pike came through in 1805. Michigan Territory Governor Lewis Cass led an expedition through the area in 1820. Explorer and scientist Joseph Nicollet created the first accurate map of the area along the river in 1836.

Missionaries were some of the area's first European settlers. Methodist missionaries settled temporarily along the Little Elk River in 1838. The Reverend Frederic and Elisabeth (Taylor) Ayer moved to the Belle Prairie area in 1849. They started a mission and school there for the Ojibwe. Father Francis Xavier Pierz came to the area in 1852 and started many communities in central Minnesota, including Sobieski and Rich Prairie (later renamed Pierz) in Morrison County.

The US legislature established the Wisconsin Territory effective July 3, 1836. It existed until its eastern portion was granted statehood (as Wisconsin) in 1848. The federal government set up the Minnesota Territory effective March 3, 1849. The newly organized territorial legislature created nine counties across the territory in October of that year. On February 25, 1856, Benton, one of those original counties, had a portion of its northern section partitioned off to create Morrison County, with Little Falls as the county seat. It was named for William and Allen Morrison, early fur trappers and traders in the area.

The event that prodded further development of the county was the building of Fort Ripley (originally named Ft. Gaines). In order to construct this military outpost, the Little Falls Mill and Land Company built a dam and sawmill in 1849. The company was formed by James Green, Allan Morrison, Henry Rice, John Irvine, John Blair Smith Todd, and Napoleon Jackson Tecumseh Dana. Fort Ripley was ostensibly built to protect the Winnebago Indians, who had been relocated by Henry Rice from Iowa to central Minnesota west of the Mississippi River, between the Crow Wing and Long Prairie rivers. Rice hoped the Winnebago would act as a buffer between the warring Ojibwe and Dakotah. His plan was unsuccessful and in 1855 the Winnebago were moved to the Blue Earth River in southern Minnesota.

The Little Falls area was first settled in 1848, and platted in 1855. Its growth occurred when the Little Falls Company (later called the Little Falls Manufacturing Company) built a second dam. This dam washed out, as had the first, and Little Falls entered a long period of economic depression and stagnant population. Bit by bit, Little Falls grew, until it was officially incorporated as a village in 1879.

Another wave of immigration occurred between 1880 and 1920. A wide variety of ethnic groups settled in Morrison County. This wave of immigration was spurred by the construction of the third dam at Little Falls in 1887. A group of investors from Louisville, Kentucky led by M. M. Williams financed the dam. To be sure their investment would succeed, they encouraged other major industries to move to the city, touting the water power.