| Charles D. Cooper | |
| Office: | Secretary of State of New York |
| Term Start: | April 16, 1817 |
| Term End: | April 24, 1818 |
| Governor: | John Tayler (acting) DeWitt Clinton |
| Predecessor: | Robert L. Tillotson |
| Successor: | John Van Ness Yates |
| Birth Name: | Charles DeKay Cooper |
| Birth Date: | 1769 |
| Birth Place: | Rhinebeck, Dutchess County, New York |
| Parents: | Ananias Cooper Elizabeth DeKay |
| Spouse: | Margaret Vernor Tayler |
| Children: | 5 |
Charles DeKay Cooper (1769 - January 30, 1831) was an American physician, lawyer and Democratic-Republican politician.
Born in Rhinebeck, New York, he was the son of Dr. Ananias Cooper and Elizabeth DeKay Cooper.
He studied medicine with Dr. Crosby in New York City and became a physician, like his father. By 1791, Cooper had settled in Albany. In 1792, he began to practice medicine.
In 1794, he was appointed Health Officer of the Port of Albany
In February 1804, Cooper attended a dinner party during which Alexander Hamilton spoke forcefully and eloquently against the Federalists' plan to nominate Aaron Burr as their candidate for Governor of New York. Cooper later wrote a letter to Philip Schuyler, Alexander Hamilton's father-in-law, in which he made reference to the "despicable opinion" Hamilton had expressed about Burr. The letter was published in The Albany Register, but was tame compared to other attacks on Burr in the press. Still, Cooper's letter proved the last straw in the ongoing rivalry between Burr and Hamilton. When Burr read the letter weeks later, shortly after his defeat in the governor's race, he was enraged by Hamilton's alleged remarks, and challenged Hamilton to a duel, in which Hamilton was killed.
From March 1806 to June 1807, Cooper was First Judge of the Albany County Court. From 1815 to 1816, he was a member of the Erie Canal Commission. In April 1817, while his father-in-law was Acting Governor, Cooper was appointed Secretary of State of New York.
He married Margaret Vernor ( - 1860), the adopted daughter of the future Lt. Gov. John Tayler and the former Margarita Van Valkenburgh. They had five children, including:
Cooper died on January 30, 1831. He was buried in the Dutch Reformed section of the State Street Burying Grounds, but his remains were later removed to a family plot in the Albany Rural Cemetery.