Margaret Brown Klapthor (January 16, 1922, Henderson, Kentucky – September 26, 1994, Washington, D.C., USA) was a curator of the Smithsonian Institution's First Ladies collection[1] and an expert on the history of the White House.

She then joined the Smithsonian Institution as a scientific aide, working in the Civil Section of the Division of History at the United States National Museum.

[6] She collaborated with her father Paul Dennis Brown on The History of Charles County, Maryland, written in its Tercentenary Year of 1958.

[6] She located Dolley Madison's inauguration gown, and arranged for its indefinite loan to the Smithsonian from the William Rockhill Nelson Gallery of Art in Kansas City, Missouri.

She also wrote The First Ladies Cook Book: Favorite Recipes of All the Presidents of the United States (1965), which was repeatedly republished.

New York Times food critic Craig Claiborne wrote that it was "perhaps the most comprehensive and detailed volume ever written" about the dining habits of American Presidents and their wives.