Incumbent Republican Sen. Joni Ernst, first elected in 2014, announced her retirement in September 2025 following public backlash to comments made at a town hall event. Congresswoman Ashley Hinson is heavily favored to win the Republican nomination to succeed her, while Democrats are expected to field State Senator Zach Wahls, State Representative Josh Turek, and broadcaster Nathan Sage as potential challengers.

Iowa, once a reliable swing state, has trended sharply Republican since 2016 after twice supporting Barack Obama. In the 2024 presidential election, Donald Trump won Iowa by 13 points—the largest margin for any candidate in the state since 1972 and the first Republican double-digit victory since 1980. Republicans currently control every statewide office except auditor, both legislative chambers, and the entire congressional delegation.