The county was established in 1854 and named after Stephen A. Douglas (1813–1861), who was then serving as a U.S. senator from Illinois.

[2][3] Douglas County is part of the Omaha-Council Bluffs, NE-IA Metropolitan Statistical Area.

[4] In the Nebraska license plate system, Douglas County was represented by the prefix "1" (as it had the largest number of vehicles registered in the state when the license plate system was established in 1922).

As of the 2010 United States Census, there were 517,110 people and 206,522 households in the county.

As of the 2000 United States Census, there were 463,585 people, 182,194 households, and 115,146 families in the county.

29.80% of all households were made up of individuals, and 8.70% had someone living alone who was 65 years of age or older.

However, it has become a far more competitive county in national elections compared to the rest of the state in the last ten years.

Barack Obama won a majority of the county's votes in 2008, becoming the first Democrat to do so since 1964.

He also narrowly carried the 2nd congressional district as well, garnering him one electoral vote statewide.

It swung back to the Republican column in 2012 with Mitt Romney winning the county by an even closer majority.

The county swung back to Democratic hands in 2016 with Hillary Clinton winning a plurality of its votes, but unlike Obama eight years prior she failed to carry the 2nd congressional district.