Janet Annenberg Hooker (1904–1997) was an American philanthropist.
She was born in Chicago to Sadie and Moses Annenberg; Moses was the founder of a publishing empire based on The Daily Racing Form and The Philadelphia Inquirer. She was third of eight children (seven girls and a boy) born to the couple. Their names were Diana Annenberg (1900–1905), Esther “Aye” Annenberg Simon Levee (1901–1992), Enid Annenberg Haupt (1906–2005), Walter H. Annenberg (1908-2002), Lita Annenberg Hazen (1909–1995), Evelyn Annenberg Jaffe Hall (1911–2005), and Harriet Beatrice Annenberg Ames Aronson (1914–1969).
She contributed $5 million of the $10 million cost of the Janet Annenberg Hooker Hall of Geology, Gems and Minerals, which opened in 1997, and which is the most comprehensive Earth sciences complex of its kind. It is part of the National Museum of Natural History. The Hope Diamond (among other things) is now on permanent display there.
Her first gift to the National Museum of Natural History was the Hooker Emerald Brooch, which she donated in 1977, when it was valued at US$500,000. She later gave the museum the Hooker Starburst Diamonds.
She also paid for the redecoration of the Blue Room at the White House, and she donated the Lobby Colonnade of the Metropolitan Opera in memory of her mother.
She was married three times—first in 1924 to publisher L. Stanley Kahn (divorced 1937), then in 1938 to investment banker Joseph A. Neff (died 1969), and lastly in 1974 to James Stewart Hooker, head of labor relations for the Philadelphia Inquirer (died 1976).