George Templeton Strong (January 26, 1820 – July 21, 1875) was an American lawyer, musician and diarist. His 2,250-page diary, discovered in the 1930s, provides a striking personal account of life in the 19th century, especially during the events of the American Civil War. It covers 1835 to 1875. The historian Paula Baker described him as "perhaps the northern equivalent of South Carolina's Mary Chesnut: quotable, opinionated, and a careful follower of events." He was a well-placed civic leader who was very well known in New York City. He served with distinction on the United States Sanitary Commission during the Civil War. But he never occupied top positions and had no special influence.