Muriel McQueen Fergusson, (May 26, 1899 – April 11, 1997) was a Canadian activist, judge and politician. Fergusson served in the Senate of Canada and as the first woman Speaker of the Senate. She is known for a long career of advocating for the less privileged, most often women. In 1926, she retired from only one year's practice at law in the office of her barrister father, James McQueen, to marry Aubrey S. Fergusson. She lived with her husband in Grand Falls, New Brunswick, for ten years, during which time she opened the Malabeam Tea Room, and organized community activities including founding the Grand Falls Literary Club. She was readmitted to the bar in 1936 to support her family after her husband became ill from earlier injuries acquired during service in the First World War; he died six years later. She gradually took over her husband's practice and soon after became New Brunswick's first female judge of a probate court. She also became clerk of the county court and the circuit court and the town solicitor for Grand Falls.
She was the first woman elected, in 1950, to the Fredericton City Council as a city councilor and was the first woman deputy mayor in 1953.
Honorary doctor of several Canadian universities; among others, she received an honorary degree from Mount Allison University in 1954. A charitable foundation and a family violence research centre are named in honour of Muriel McQueen Fergusson.