Dava Sobel is an American writer of popular expositions of scientific topics. Her books include Longitude, about English clockmaker John Harrison; Galileo's Daughter, about Galileo's daughter Maria Celeste; and The Glass Universe: How the Ladies of the Harvard Observatory Took the Measure of the Stars about the Harvard Computers.

Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time is a 1995 best-selling book by Dava Sobel about John Harrison, an 18th-century clockmaker who created the first clock (chronometer) sufficiently accurate to be used to determine longitude at sea—an important development in navigation. The book was made into a television series entitled Longitude. In 1998, The Illustrated Longitude was published, supplementing the earlier text with 180 images of characters, events, instruments, maps and publications.