1938 United States Senate election in Wisconsin

The 1938 United States Senate election in Wisconsin was held on November 8, 1938. Incumbent Democratic U.S. Senator F. Ryan Duffy ran for a second term in office. In a three way race, Alexander Wiley defeated Duffy and Lieutenant Governor Herman L. Ekern.

Primary elections were held on September 20. Senator Duffy was unopposed for the Democratic nomination. The Republican primary was a rematch of the 1936 gubernatorial primary; Wiley defeated John B. Chapple, who had been nominated in the previous two Senate races. After losing, Chapple entered the general election as a candidate advocating for the Townsend Act. In the Progressive primary, Ekern defeated Thomas R. Amlie by roughly 9,091 votes.

Candidates

 * F. Ryan Duffy, incumbent senator since 1933

Candidates
[[File:1938 WI Progressive Senate Primary election in Wisconsin results map by county.svg|thumb|Results by county:{{legend|#e27f7f|Ekern}}
 * Thomas R. Amlie, U.S. Representative from Beloit
 * Herman L. Ekern, Lieutenant Governor of Wisconsin

{{legend|#E27F7F|50–60%}}

{{legend|#D75D5D|60–70%}}

{{legend|#D72F30|70–80%}}

{{legend|#C21B18|80–90%}}{{legend|#5FD35F|Amlie}}

{{legend|#5FD35F|50–60%}}

{{legend|#37C837|60–70%}}

{{legend|#2CA02C|70–80%}}

{{legend|#217821|80–90%}}]]

Candidates

 * William J. Campbell, nominee for U.S. House from Oshkosh in 1934
 * John B. Chapple, nominee for Senate in 1932 and 1934 and candidate for governor in 1936
 * Stephen J. McMahon, former judge of the United States Board of Tax Appeals
 * Edward J. Samp, former University of Wisconsin–Madison football star and candidate for Treasurer in 1930
 * William Henry Stafford, U.S. Representative from Milwaukee
 * Alexander Wiley, nominee for governor in 1936

Candidates

 * Fred Basset Blair, bookseller and perennial candidate (Communist)
 * John B. Chapple, perennial candidate (Townsend Republican)
 * F. Ryan Duffy, incumbent senator since 1933 (Democratic)
 * Herman L. Ekern, Lieutenant Governor of Wisconsin (Progressive)
 * Joseph Ehrhardt, perennial candidate (Socialist Labor)
 * Alexander Wiley, nominee for governor in 1936 (Republican)