The 1920 Iowa Senate elections took place as part of the biennial 1920 United States elections. Iowa voters elected state senators in 29 of the senate's 50 districts. State senators serve four-year terms in the Iowa Senate. A statewide map of the 50 state Senate districts in the 1920 elections is provided by the Iowa General Assembly here. The primary election on June 7, 1920, determined which candidates appeared on the November 2, 1920 general election ballot. Following the previous election, Republicans had control of the Iowa Senate with 45 seats to Democrats' 5 seats.