Seward County is a county located in the U.S. state of Nebraska. As of the 2010 census, the population was 16,750. Its county seat is Seward. The county was formed in 1855 and later organized in 1867. It was originally called Greene County, and in 1862 it was renamed in honor of William H. Seward, United States Secretary of State under Abraham Lincoln and Andrew Johnson. Seward County is part of the Lincoln, NE Metropolitan Statistical Area.