Olinthus Gilbert Gregory (1774-1841), English mathematician. Gregory was born near Huntingdon and was privately educated. He started publishing his ideas on mathematics and astronomy in 1793. In 1802 was appointed a mathematical master at the Royal Military Academy, Woolwich, and in 1805 was appointed professor. He wrote many books teaching mathematics to lay people and a fine biography of the baptist Robert Hall. Gregory was one of the founders of the Royal Astronomical Society.