Iowa's 1st Senate district
The 1st district of the Iowa Senate, located in Northwestern Iowa, is currently composed of part of Woodbury County. It is represented by Catelin Drey, who won an August 2025 special election to succeed Republican Rocky De Witt. On September 15, 2025, she was sworn in by Iowa Supreme Court Justice Matthew McDermott.
List of representatives
Source:Historical district boundaries
Source:| Map | Description | Years effective | Notes |
| Lee County | 1846 - 1857 | From 1846 to 1857, district numbering was not utilized by the Iowa State Legislature. This convention was added with the passing of the 1857 Iowa Constitution. Numbering of districts pre-1857 is done as a matter of historic convenience. | |
| Lee County | 1858-1970 | ||
| Plymouth County Sioux County Lyon County | 1971-1972 | In 1970, the Iowa Legislature passed an amendment to the Iowa Constitution setting forth the rules for legislative redistricting in order to abide by the rules established by the Reynolds v. Sims Supreme Court case. The first reapportionment map created by the Republican controlled legislature was deemed unconstitutional, but was still used for the 1970 election. | |
| Plymouth County Sioux County Lyon County | 1973-1982 | ||
| Woodbury County | 1983-1992 | ||
| Woodbury County | 1993-2002 | ||
| Woodbury County | 2003-2012 | ||
| Lyon CountyOsceola County Dickinson County Clay County Palo Alto County | 2013-2022 | ||
| Woodbury County | 2023–present | - |