Lawrence David O'Brien (March 31, 1951 – December 16, 2004) was a Canadian politician.
O’Brien represented Labrador in the House of Commons of Canada as a Liberal from 1996 until his death in 2004.
Born in L'Anse-au-Loup, Newfoundland and Labrador, O’Brien was an adult education instructor, a public servant, a teacher, and from 1985 to 1996, and a town councillor in Happy Valley-Goose Bay, Newfoundland and Labrador.
O'Brien was a candidate for the provincial Liberal nomination in the district of Cartwright-L'anse au Clair in 1996.
After his loss in that race, he entered, and won, the federal Liberal nomination for the by-election in the riding of Labrador, vacated by the appointment of Bill Rompkey to the Senate.