David Wiley (1768 – October 14, 1812) was an American surveyor, politician, writer, scientist, and Presbyterian minister who served as postmaster and mayor of Georgetown, District of Columbia.

David Wiley was born in 1768 in Pennsylvania.^{[citation needed]} He graduated from the College of New Jersey (later Princeton) in 1788. From 1788 to 1789, Wiley was a tutor at Hampden Sidney College in Virginia. Wiley married Susan Wynnkoop and they had four children.

Wiley was ordained as a Presbyterian minister by the Presbytery of Huntingdon on April 9, 1794, and installed as pastor of two congregations in Centre County, Cedar Creek and Spring Creek.

During this period, Wiley also served as the first stated clerk of the Presbytery. He served subsequent congregations and in temporary vacancies until April 1801, when he requested and obtained permission to move to the Presbytery of Baltimore, which covered a wide region that included Virginia.

In 1801, Wiley was requested by Stephen Bloomer Balch to move to Georgetown to succeed him as the principal and headmaster of a private school, the Columbian Academy. Wiley also taught several subjects at the academy, including philosophy, mathematics, geography, and Greek. His pupils included Thomas Bloomer Balch.

In 1802, Wiley wrote to President Thomas Jefferson encouraging the appointment of his friend William R. Cozens to be the first Librarian of Congress.

According to The Papers of Thomas Jefferson, in October 1804, Wiley, along with Abraham Bradley Jr., made a series of astronomical observations near the White House to determine its longitude and latitude.

In 1805, President Jefferson considered appointing Wiley as a leader of the Red River Expedition of the Southwestern United States.