The 1938 Iowa State Senate elections took place as part of the biennial 1938 United States elections.

A statewide map of the 50 state Senate districts in the 1938 elections is provided by the Iowa General Assembly here.

Therefore, on election day in November 1938, Republicans held 29 seats to Democrats' 21.

To claim control of the chamber from Republicans, the Democrats needed to net 5 Senate seats.

Republicans maintained control of the Iowa State Senate following the 1938 general election with the balance of power shifting to Republicans holding 38 seats and Democrats having 12 seats (a net gain of 9 seats for Republicans).