On May 25, 1812, Van Ness was nominated by President James Madison to a new seat on the United States District Court for the District of New York. He was confirmed by the United States Senate on May 26, 1812, and received his commission on May 27, 1812. On April 9, 1814, he was reassigned by operation of law to the newly subdivided United States District Court for the Southern District of New York.