Senator Tom Dempsey, a Republican, represents part of St. Charles County (District 23) in the Missouri Senate. Senator Dempsey was elected to the Senate in a 2007 special election. He was elected to the Missouri House of Representatives in 2000 and during his tenure in the House served as Chairman of the Job Creation and Economic Development Committee before serving as the Majority Floor Leader for three years. He was elected to the St. Charles City Council in 1998 and served in that capacity prior to his election to the Missouri House.

In addition to his legislative duties, Sen. Dempsey is Vice President of First National Bank of St. Louis. His family has been in the restaurant business in St. Charles County for more than fifty years.

Throughout his career he has received the following awards: the RCGA Lewis & Clark Statesman Award; St. Louis Business Journal Legislative Award, Missouri Farm Bureau Friend of Agriculture Award, Missouri Chamber of Commerce Spirit of Enterprise Award, Missouri Community College Distinguished Legislator Award, Missouri Jaycees Outstanding Young Missourian Award, Heroes for Mental Health Award from the Crider Center for Health, AIM Voice of Missouri Business Award, Missouri Association of Veterans' Organizations Award, Alzheimer's Association Leadership of the Year, the Gary Wiggins Statesman Award from the American Cancer Society, and the 2007 Champion for Children Award from the Community and Children's Resource Board of St. Charles County.

Sen. Dempsey is a member of the St. Charles and St. Peters Chambers of Commerce, St. Charles Rotary and is a member of St. Cletus Catholic Church.

He is a graduate of DeSmet Jesuit High School and received a B.A. degree in Political Science from Rockhurst University.

Born in St. Charles, Sen. Dempsey resides there with his wife, Molly, and their children: Meaghan, Abby, and Jack.