Bill Foster, a Democrat who lives in Naperville with his wife Aesook, is seeking reelection to the U.S. House of Representatives in Illinois's 11th Congressional District. The general election is Nov. 3, 2026.

Foster faces Republican Jeffrey D. Walter, according to BallotReady election data.

Foster is certified for the ballot.

Candidate information

  • Party: Democratic
  • Residence: Naperville
  • Born: Oct. 7, 1955, in Madison, Wisconsin
  • Education: Bachelor of science in physics, University of Wisconsin–Madison (1976); doctorate in physics, Harvard University (1983)
  • Family: Wife Aesook, who is also a physicist

Foster is the only PhD physicist in Congress, according to his congressional biography. His father was a civil rights lawyer who wrote much of the enforcement language behind the Civil Rights Act of 1964, according to the same biography.

Experience and public service

Foster has represented the 11th Congressional District since 2013. He previously represented the 14th Congressional District from 2008 to 2011, according to BallotReady.

Before entering Congress, Foster worked as a senior physicist at Fermi National Accelerator Laboratory from 1984 to 2006. He was a member of the team that discovered the top quark, the heaviest known form of matter, according to his congressional biography. He also led teams that designed and built several scientific facilities, including the Antiproton Recycler Ring.

In 1998, Foster was elected a Fellow of the American Physical Society, according to his Wikipedia biography. He and Stephen D. Holmes received the Robert R. Wilson Prize for Achievement in the Physics of Particle Accelerators in 2022.

Foster said on his campaign website that his business career began at age 19, when he and his younger brother Fred started a company in their basement with $500 from their parents. That company, Electronic Theatre Controls, Inc., now manufactures over half of the theater lighting equipment in the United States, according to Foster's campaign.

He serves as ranking member of the Subcommittee on Financial Institutions on the House Financial Services Committee. He is also a member of the House Science, Space, and Technology Committee.

On the issues

Foster's policy positions below are drawn from his campaign website and public records.

Healthcare: Foster said on his campaign website that he believes health care is a basic human right. He said he has voted for a public option to compete with private insurance plans and is committed to strengthening the Affordable Care Act. He said he is focused on strengthening Medicare and reducing prescription drug prices.

Climate and energy: Foster said he believes global warming is human-caused and dangerous. He said he supports expanding federal research and development for pre-commercial energy technologies and incentivizing public-private partnerships. Foster said on his campaign website that he believes nuclear power can be made safe.

Gun safety: Foster said he supports a ban on assault weapons and universal background checks. He said he supports the Zero Tolerance for Domestic Abusers Act, which would bar convicted stalkers from buying or owning firearms.

Reproductive rights: Foster said on his campaign website that the decision to have an abortion is best left between a woman and her doctor. He said he is committed to passing legislation to codify the protections of Roe v. Wade.

Government reform: Foster said he supports a constitutional amendment to overturn the Citizens United Supreme Court decision. He said he supports legislation to increase disclosure of donors to Super PACs and other groups.

Endorsements

The following organizations have endorsed Foster, according to BallotReady:

  • International Brotherhood of Electrical Workers Local 134
  • International Union of Operating Engineers Local 399
  • Chicago Federation of Labour
  • JStreetPAC
  • AFL-CIO
  • IUOE Local 150
  • Illinois NOW PAC
  • DuPage County Democrats
  • Humane Society of the United States
  • Jewish Democratic Council of America
  • GiveGreen
  • 314 Action
  • United Hellenic Voters of America

The Naper Today candidate questionnaire was sent to Bill Foster's campaign. No response was received as of Oct. 9, 2026. The policy positions above are drawn from his public campaign website and public records.