Bert Robert Lewis, Sr. (November 11, 1931 – April 25, 1979) was an American veterinarian and politician.
He received his degrees in animal husbandry in 1953, biological science in 1958, and in veterinarian medicine in 1960 from Kansas State University.
Lewis served in the United States Army during the Korean War.
Lewis served in the Minnesota Senate from 1973 until his death in 1979 and was a Democrat.
He died from a heart attack at his home in Golden Valley, Minnesota.