Tim Johnson (born December 29, 1946, in Canton, South Dakota) is a United States Senator from South Dakota. He is the senior Senator from that state, and a member of the Democratic Party.
Born in Canton, South Dakota, Johnson earned a B.A. in 1969 and an M.A. in 1970, both from the University of South Dakota, where he was a brother of Delta Tau Delta. After doing post-graduate studies at Michigan State University from 1970-71, he earned a J.D. from the University of South Dakota in 1975. He served in the South Dakota House of Representatives from 1979-82 and in the South Dakota Senate from 1983-86. He served in the United States House of Representatives, representing South Dakota at-large, from 1987-97.