John Watts Cady (28 June 1790 – 5 January 1854) was a member of the US House of Representatives (NR-NY 16) from 4 March 1823 to 3 March 1825, succeeding Joseph Kirkland and preceding Henry Markell. Born in Florida, New York, the nephew of Daniel Cady, he practiced law in Johnstown before serving as town clerk, county supervisor, in the state assembly from 1821 to 1822, in Congress, and as Fulton County district attorney from 1840 to 1846.