Charles Dewey Day was born on May 6, 1806, in Bennington, Vermont.

He was a lawyer, politician, judge, and educationalist. In 1812, he came to Montreal in Lower Canada with his family and they moved again to Hull in 1828. Charles studied in Montreal, articled in law, and was called to the bar in 1827. He practiced mainly in the Ottawa valley, representing lumber merchants. In 1838, he was named Queen's Counsel. He spoke publicly against Papineau's Ninety-Two Resolutions in 1834. In 1840, he was appointed solicitor general in the Special Council of Lower Canada up until the union of the two Canadas in 1841, when he was elected to represent the Canada East constituency of Ottawa in the Legislative Assembly of the Province of Canada and named solicitor general in the Executive Council for the province. In 1850, he was appointed to the Superior Court. From 1852 to 1884, he served as president of the Royal Institution for the Advancement of Learning in the province. From 1859 to 1865, he helped develop the civil code for Lower Canada. He served as Acting Principal of McGill College (1853-1855), 1st Chancellor of McGill University (1864-1884) and helped establish its faculty of law in 1848. Not only was Day the architect of McGill’s mid-century revival, but he also guided it through numerous legal and political difficulties. In 1868, he represented Quebec when the assets and liabilities of Upper and Lower Canada were divided after Confederation. In 1873, he investigated charges of corruption against the government in the Pacific Scandal.

In 1830, he married Barbara Lyon and in 1853, he remarried Maria Margaret Holmes (1829–). He died on January 31, 1884, in Newton, Devon, England, during a visit and is buried there.