William Henry Farquhar (June 14, 1813 – February 17, 1887) was an American who was influential in the development of Montgomery County, Maryland.
William had a brother-in-law and sister, Benjamin Hallowell and Mary W. Kirk (née Farquahar), respectively.
Farquhar, fond of books and a student from his earliest years, completed his education with Hallowell in Alexandria, Virginia, at the Brimstone Academy.
He was also a county surveyor, civil engineer, president of the Sandy Spring Lyceum from 1872 to 1873, and one of the original directors of the Mutual Fire Insurance Company from 1848 to 1885.
For the rest of his life, he lived on his farm with his grandchildren and wife, where he published several books and remained influential with the Montgomery County School Board.