Dr. David D. Demarest (July 30, 1819 – June 21, 1898) was an American author and theologian from New Brunswick, New Jersey.

[1][2] Demarest was born in Oradell, New Jersey on July 30, 1819, of Dutch and Huguenot background.

[3] After graduation from the seminary, Demarest was the pastor at several Reformed Church of America congregations.

They had seven children, including William Henry Steele Demarest, who would become president of Rutgers College.

[4] He died on June 21, 1898, at his home in New Brunswick and is buried at the Elmwood Cemetery.