Dr Eileen Joyce Harris (born 1931) is an American/English architectural historian and author.

Eileen Harris (née Spiegel) was born in November 1932 to Paul Spiegel (20 June 1904 - 15 June 1991) and Irene Stein (14 September 1900, Russia - 25 December 1991) in the city of Brooklyn, New York.

Eileen also has a younger brother, Michael Ivan Spiegel (25 December 1934, Brooklyn, New York - 3 August 2012, San Francisco, California), who was a famous antitrust lawyer and also Deputy Attorney General of California for 25 years.

Harris is an internationally recognised Robert Adam scholar, publishing extensively on the subject for over 40 years.

Harris, along with Nicholas Savage (of the Royal Academy Library), has been working part-time on an integrated catalogue of Sir John Soane's art, architectural and general volumes and pamphlets in his library at Sir John Soane's Museum, being made available online.