Lawrence Arthur Dumoulin Cannon (April 28, 1877 – December 25, 1939) was a Canadian lawyer, politician, and Puisne Justice of the Supreme Court of Canada.

Born in Arthabaska, Quebec, the son of Lawrence John Cannon and Aurélie Dumoulin, he received a Bachelor of Arts degree in 1896 from Université Laval.

In 1916, he was elected to the Legislative Assembly of Quebec for the riding of Québec-Centre as a Liberal.

He returned to private practice until he was appointed to the Court of King's Bench of Quebec in 1927.

His great-nephew Lawrence Cannon was a Member of Parliament from 2006 to 2011, serving in Prime Minister Stephen Harper's cabinet.