Brian W. Stewart (born October 25, 1957) was a Republican member of the Illinois Senate representing the 45th District since his election in 2018.

The 45th District encompasses all of Stephenson, Jo Daviess, and Ogle counties as well as portions of Winnebago, DeKalb, LaSalle, Lee, Whiteside, and Carroll.

[citation needed] He attended Freeport High School, Stewart enlisted in the United States Army.

[citation needed] Today, he owns several businesses and is a major employer in Northwest Illinois.

He was sworn in early on December 5, 2018, to represent the 45th District, which encompasses all of Stephenson, Jo Daviess, and Ogle counties as well as portions of Winnebago, DeKalb, LaSalle, Lee, Whiteside, and Carroll.