Martin George Southcote Mansergh (born 31 December 1946) is an Irish former Fianna Fáil politician who served as a Minister of State from 2008 to 2011. He served as a Teachta Dála (TD) for the Tipperary South constituency from 2007 to 2011. He was a Senator for the Agricultural Panel from 2002 to 2007. He played a leading role in developing Fianna Fáil policy on Northern Ireland.