Sibley & Marble (Clark Sibley & Simeon Marble), clock and watchmakers working in New Haven, Connecticut.

Sibley & Marble (Clark Sibley and Simeon Marble) are documented in American Clocks Volume 3: American Clockmakers & Watchmakers, authored by Sonya L. Spittler, Thomas J. Spittler, and Chris H. Bailey. According to this reference, the partnership operated in New Haven from April 1801 to 1807, with their business located on Chapel Street, two doors west of Messrs. Street & Hughes. The partnership concluded upon Sibley's death in 1807. Sibley served as the firm's principal clockmaker. The firm advertised services as clock and watchmakers and promoted their capacity to manufacture steeple clocks priced between $200 and $1,000. They also offered eight-day house clocks with moon and plain faces, warranted timepieces, and clock and watchmakers' lathes and engines. Their advertisements stated: "Swords and cutlasses mounted with brass or silver in the best manner. Clocks & Watches, Mathematics & Surgeon's Instruments carefully repaired." After the partnership ended, Marble continued in the jewelry and silverware retail business for many years.

Clark Sibley was born on August 15, 1777, in Sutton, Massachusetts, to Abner and Betty (Lillie) Sibley. He began his apprenticeship in clockmaking under Major Josiah Wheelock, a silversmith and watchmaker in Sutton. Sibley died in New Haven, Connecticut, on October 19, 1807.

Simeon Marble was born in Sutton, Massachusetts, on November 5, 1777. He apprenticed in clockmaking under Major Josiah Wheelock, a silversmith and watchmaker in Sutton. Marble married Susaana Bishop (1784–1861) on January 12, 1797. He is recorded as working as a silversmith in New Haven in 1807. Marble formed a partnership with Clark Sibley in 1801. After Sibley's death in 1807, Marble continued to work as a silversmith, selling gold and silver wares, and also practiced dentistry. Simeon Marble died in New Haven, Connecticut, on October 27, 1856.