Dean M. Mortimer is an American politician who served as a Republican member of the Idaho Senate, where he as represented the 30th district from 2012 to 2020 and served as chairman of the education committee. He previously represented District 32 in the Idaho Senate from 2008 to 2012. He was a member of the Idaho House of Representatives from 2006 to 2008, representing the District 32 Seat B.