[3][4] It was named for George H. Walsh (1845–1913), a newspaperman and politician in Grand Forks.

In 1946, Walsh County was the site of one of North Dakota's deadliest tornadoes.

[5] The storm killed 11 people, including eight in Walsh County, one in Manitoba, and two in Minnesota.

[5] Walsh County lies on the eastern side of North Dakota.

The Red River flows northward along the east side of the county on its way to Hudson Bay in Canada.

[6] The terrain generally slopes to the north and east, but the highest point is its northwestern corner, at 1,647 ft (502 m) ASL.

[8] As of the first quarter of 2024, the median home value in Walsh County was $123,610, an increase of _% from the prior year.

In terms of ancestry, 39.7% were Norwegian, 21.6% were German, 11.0% were Polish, 9.4% were Irish, 9.3% were Czech, 5.8% were English, and 5.4% were American.

In only one national election since 1964 has the county selected the Democratic Party candidate (as of 2024).