Mary Louise McDonald (born on 1 May 1969) is an Irish republican politician. She has been a Teachta Dála (TD) since 2011, currently for the Dublin Central constituency. She previously served as a Member of the European Parliament (MEP) for the Dublin constituency constituency from 2004 to 2009. Originally a member of Fianna Fáil, she left the party in 1998. During this time she also served as Leas-Chathaoirleach (Vice-Chair) of the Irish National Congress republican organisation.