Lorna Ann Milne (born December 13, 1934) was a Canadian Senator from 1995 to 2009.
Milne is the daughter of former Mayor of Toronto and Co-operative Commonwealth Federation (CCF) Member of Provincial Parliament (MPP) William Dennison and grand-daughter of Isaac Bainbridge, early labour organizer and pacifist. Her husband, William Ross Milne, served as a Liberal federal Member of Parliament in the 1970s.
Lorna Milne lectured in physics at the University of Guelph in the 1950s prior to marrying and having children. In the 1960s she became a political and community activist serving as a school trustee from 1964 to 1972 as well as being active in a number of community organizations and charities in Peel Region outside of Toronto. She served as president of the North Peel unit of the Canadian Cancer Society in the 1980s and as president of her Liberal riding association.
In 1995, she was appointed to the Senate on the advice of Prime Minister Jean Chrétien. In the Senate, she served as chair of the Legal and Constitutional Affairs Committee, and waged a seven year campaign from 1998 to 2005 to allow historical census data to be released to the public. It culminated when Bill S-18 was passed, ensuring that all censuses conducted until 2001 would be released after 92 years, and all subsequent censuses starting with the 2006 census would allow Canadians the option to decide whether or not their information would be released. She also served as Chair of Committee on Rules, Procedures and the Rights of Parliament when it successfully recommended creation of the position of Senate Ethics Officer. She was also responsible for the legalization of hemp as an agricultural crop in 1999.
Milne served as Senate Vice-Chair of the National Liberal Caucus from 2006–2009 and also was President of the Canada-Europe Parliamentary Association from 2004-2008.
In 2009, Lorna Milne retired from the Senate upon reaching the mandatory retirement age of 75.