The 1970 Iowa State Senate elections took place as part of the biennial 1970 United States elections. Iowa voters elected state senators in 27 of the state senate's 50 districts. Due to redistricting following the amending of the Iowa Constitution in 1968 mandating single-member districts, the Iowa Senate downsized from 61 to 50 members following the 1970 election. State senators typically serve four-year terms in the Iowa State Senate. To claim control of the chamber from Republicans, the Democrats needed to net 9 Senate seats.