March 3, 1931
Special Election to fill the vacancy created by the resignation of Senator Roy Fellom (SD-21). Senator Fellom had resigned from SD-21 (to which he had been elected in 1928) to assume the SD-14 seat (to which he had been elected in 1930).
|Frederick Carsten Gerdes||Nonpartisan||12.8%||Loss|
|Elmer E. Robinson||Nonpartisan||29.7%||Loss|
|Timothy E. Treacy||Nonpartisan||36.9%||Win|