Margaret Vandemore Gillespie (born February 15, 1969) is an American politician. She was a Democratic member of the South Dakota House of Representatives from 2001 to 2008, and a Democratic member of the South Dakota Senate from 2009 to 2010, representing South Dakota's 16th district. Her district included Lincoln and Union counties.
Gillespie received a B.A. from Augustana College in 1991 and a J.D. from the University of South Dakota School of Law in 1996. Gillespie is an attorney living in Hudson, South Dakota.