Harrison Gray Otis Dwight (1803–1862) was an American Congregational missionary.
Harrison Gray Otis Dwight was born on November 22, 1803 in Conway, Massachusetts. His father was Seth Dwight (1769–1825) and mother was Hannah Strong (1768–1813).
He graduated from Hamilton College in 1825 and went on to study theology at Andover Theological Seminary where he graduated in 1828. He married Elizabeth Barker (1806–1837) on January 4, 1828. She died of Cholera in 1837 with her third son. They were both buried in the Protestant cemetery of San Stefano (now Yeşilköy), in Istanbul. He was ordained on July 15, 1829 as a missionary for the American Board of Commissioners for Foreign Missions. He was sent to assist in the Armenian missions serving in Constantinople for over 30 years. He wrote: Christianity Revived in the East (1850). In 1856, Dwight published a "Manual of Christian Theology" in Constantinople in association with George Warren Wood and Rev. Dr. Edward Riggs. Children from his first wife were:
He married Mary Lane (1811–1860) on April 6, 1839. Their children were:
His older sister Harriet Dwight (1792–1870) married James Dana, and their son was geologist James Dwight Dana (1813–1895). He died on January 25, 1862.