Liam Thomas Cosgrave (born 30 April 1956) is an Irish former Fine Gael politician who served as Leas-Chathaoirleach of Seanad Éireann from 1997 to 2002, Cathaoirleach of Seanad Éireann from 1996 to 1997 and a Senator for the Industrial and Commercial Panel from 1993 to 2002. He previously served as a Teachta Dála (TD) for the Dún Laoghaire constituency from 1981 to 1987. Coming from a political family, he is the son of Taoiseach Liam Cosgrave and grandson of the first President of the Executive Council W. T. Cosgrave.