| Lawrence Arthur Dumoulin Cannon | |
| Office1: | Puisne Justice of the Supreme Court of Canada |
| Predecessor1: | Pierre-Basile Mignault |
| Successor1: | Robert Taschereau |
| Nominator1: | William Lyon Mackenzie King |
| Term Start1: | January 14, 1930 |
| Term End1: | December 25, 1939 |
| Office2: | Member of the Legislative Assembly of Quebec for Québec-Centre |
| Predecessor2: | Eugène Leclerc |
| Successor2: | Pierre-Vincent Faucher |
| Term Start2: | 1916 |
| Term End2: | 1923 |
| Birth Date: | 28 April 1877 |
| Birth Place: | Arthabaska, Quebec, Canada |
| Death Place: | Ottawa, Ontario, Canada |
| Restingplace: | Cimetière Notre-Dame-de-Belmont |
| Spouse: | Mary Corrine Fitzpatrick |
| Party: | Liberal |
| Relations: | Lucien Cannon, brother |
| Children: | Charles-Arthur Dumoulin Cannon |
| Alma Mater: | Université Laval |
| Profession: | Lawyer |
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 1899 he received an LL.L also from Université Laval. He was called to the Bar in 1899 and practised law. His brother was Lucien Cannon, a politician and cabinet minister.
In 1908, he was elected to the City council of Quebec City. In 1916, he was elected to the Legislative Assembly of Quebec for the riding of Québec-Centre as a Liberal. He was re-elected in 1919 but was defeated in 1923.
He returned to private practice until he was appointed to the Court of King's Bench of Quebec in 1927. He was appointed to the Supreme Court in 1930 and served until his death in 1939.
His great-nephew Lawrence Cannon was a Member of Parliament from 2006 to 2011, serving in Prime Minister Stephen Harper's cabinet.