| State Senate: | Iowa |
| District: | 1st |
| Term Start: | January 13, 2003 |
| Term End: | January 9, 2011 |
| Preceded: | Steven D. Hansen |
| Succeeded: | Rick Bertrand |
| State House2: | Iowa |
| District2: | 2nd |
| Term Start2: | January 9, 1995 |
| Term End2: | January 13, 2003 |
| Preceded2: | Patrick Gill |
| Succeeded2: | Roger Wendt |
| Birth Name: | Steven Henning Warnstadt |
| Birth Date: | 2 August 1967 |
| Birth Place: | Sioux City, Iowa |
| Party: | Democratic |
| Spouse: | Mary |
| Children: | Stephanie and Jackson |
| Residence: | Sioux City, Iowa |
| Occupation: | Intelligence Officer, Instructor |
| Website: | Warnstadt's website |
Steven Henning "Steve" Warnstadt (born August 2, 1967) was the Iowa State Senator from the 1st District. A Democrat, he has served in the Iowa Senate from 2003 until 2011. He received his BA from Drake University and his MA from Temple University, and is serving as an adjunct instructor with Western Iowa Tech Community College and as an intelligence officer with the Iowa Army National Guard.
Warnstadt served on several committees in the Iowa Senate: the Appropriations committee; the Judiciary committee; the Transportation committee; the Veterans Affairs committee, where he is vice chair; and the Commerce committee, where he is chair. He also serves as vice-chair of the Transportation, Infrastructure, and Capitals Appropriations Subcommittee. His prior political experience includes serving as a representative in the Iowa House from 1995 to 2003, serving on the Woodbury County Democratic Central Committee in 1996, and serving as president of the Drake College Democrats from 1987 to 1988.
Warnstadt did not seek re-election in 2010.[1]
*incumbent