(October 13, 1769 – January 25, 1844) was the first licensed American dentist and dentistry school founder.

After working as a cabin boy, architect and schoolteacher, Hayden consulted with John Greenwood, George Washington's personal dentist, in 1795 in New York City.

Dr. Hayden was issued a license by the Medical and Chirurgical Faculty of Maryland in 1810, the first for the practice of dentistry in the United States of America.

Between 1819 and 1825, he delivered a series of lectures on dentistry to medical students at the University of Maryland, the first in the new world.

In 1820, as a pioneer geologist and botanist, he published the first general work on geology to be printed in the United States.