David Howard Senjem (/ˈsɛndʒəm/ SEN-jəm; born December 20, 1942) is an American politician currently serving on the Olmsted County Board of Commissioners. He is a former member of the Minnesota Senate, in that office from 2003 to 2023. He served as its majority leader from 2011 to 2013. A moderate Republican, Senjem has crossed party lines on many occasions, notably environmental policy and women's issues. He represented District 25, which at the time included portions of Dodge and Olmsted counties in the southeastern part of the state. Much of the northern half of Rochester was in his district.

In April 2022, Senjem announced that he would not seek reelection to the Minnesota Senate,^[1] and later announced that he would instead run for Olmsted County Commissioner for District 2.^[2]

Senjem grew up in Hayfield, Minnesota and attended Hayfield High School. After graduating, he earned a Bachelor of Arts degree from Luther College in Decorah, Iowa. He served on the Rochester City Park Board for five years, then on the Rochester City Council from 1992 to 2002. He is a retired Environmental Affairs Officer for the Mayo Clinic in Rochester.^[3]

Senjem's family originates from Bingen, Buskerud County, Norway; the original family name was Sønju. His great-great-grandfather John N. Hanson served as a Republican state representative from Dodge County from 1873 to 1874.^[3]

Senjem is generally regarded as a moderate and centrist Republican. He has been reelected multiple times even when his district backed Democratic candidates in other races.^[4] He has received praise from both sides for his bipartisanship. In January 2021, Democratic Attorney General Keith Ellison described Senjem as "open-minded" and said, "In an age where the parties are as polarized as at any point in our nation's history, Senjem is a guy who's willing to work across the aisle."^[5]

Senjem was first elected in 2002, and was reelected in 2006, 2010, 2012, 2016, and 2020. He served as minority leader from 2007 until January 3, 2011.^[3][13] On December 27, 2011, Senjem was elected majority leader after the previous majority leader, Amy Koch, resigned over an affair with a Senate staffer.^[14] Senjem became the third person to serve as both minority and majority leader, and the first to serve in both roles as a Republican.

Senjem tested positive for COVID-19 in November 2020. Upon finding out, the Minnesota Senate Republican chief of staff warned other Republicans of the positive test, but did not tell Democratic state legislators about the positive test, thus preventing them from taking the appropriate precautions.^[15]