Daniel P. O'Hare (c. 1866 - April 3, 1921) was a map draftsman and engraver for the General Land Office. Born in Washington, D.C., to an Irish father and an American mother, O'Hare worked for the U.S. Geological Survey and the General Land Office until his death. He appeared in the Washington D.C. city directory as an engraver beginning in the late 1880s but was not associated with the Geological Survey until 1890, which does not necessarily mean he wasn't working for the Geological Survey before 1890.