Daniel Laing, Jr. (died 1869) was born in Boston, Massachusetts and had been an independent printer before applying to Harvard Medical School. He asked the Boston Colonization Society for assistance to go to Liberia, and was urged by the Society to study medicine. His application to Harvard Medical School included recommendations from local clergy, the Boston Colonization Society, and Dr. Henry Clarke, a physician associated with Massachusetts General Hospital.
After his expulsion from Harvard Medical School, Laing studied under the French surgeon Alfred-Armand-Louis-Marie Velpeau in Paris, at the Royal College of Surgeons from 1852 to 1853, and finished his medical degree in 1854 at Dartmouth Medical School. He worked as a physician for the American Colonization Society thereafter and died in Charleston, SC in 1869.