Jefferson County is a county located in the U.S. state of Iowa. As of the 2020 United States Census, the population was 15,663. The county seat is Fairfield. The county was formed in January 1839, and was named for U.S. President Thomas Jefferson.

The 1996 United States presidential election in Iowa took place on November 5, 1996, as part of the 1996 United States presidential election. Voters chose seven representatives, or electors to the Electoral College, who voted for president and vice president.