Calvin Woodrow Ruck (September 4, 1925_October 19, 2004) was an activist and Canadian senator.

He was born in Sydney, Nova Scotia in 1925; his parents had come to Canada from Barbados. He left school after Grade 10 and worked as a labourer in Sydney and then as a porter on the Canadian National Railway from 1945-1958. Ruck also owned and operated a corner store in Halifax. From 1968 to 1981, he worked as a Community Development worker with the Province of Nova Scotia.

He held a number of positions within the Nova Scotia Association for the Advancement of Coloured People and was a member for most of his adult life. In the 1950s and 1960s, he organized campaigns against businesses in the Dartmouth area, including barber shops, which refused to serve black people.

In 1979, at the age of 54, he received a diploma from the Maritime School of Social Work at Dalhousie University. The School of Social Work now awards a Calvin W. Ruck scholarship each year. He worked with the Nova Scotia Human Rights Commission from 1981 to 1986. He was awarded the Governor General's Commemorative Medal in 1992 for his work in the community.

Ruck published two books about Canada's No. 2 Construction Battalion, the only all-black battalion to serve in World War I:

• Canada's Black Battalion: No. 2 Construction, 1916-1920 (ISBN 0-921201-00-1)
• The black battalion : 1916-1920 : Canada's best kept military secret (ISBN 0-920852-92-0)

He was named to the Order of Canada in 1994. In 1998, he was appointed to the Senate of Canada by Prime Minister Jean Chrétien. In 2000, at the mandatory retirement age of 75, he retired from the Senate.

He died at home in Ottawa at the age of 79.