Fred Hartsook (26 October 1876 – 30 September 1930) was an American photographer and owner of a California studio chain described as “the largest photographic business in the world” at the time, who counted Henry Ford, Charles Lindbergh, Mary Pickford, and sitting President Woodrow Wilson among his celebrity clients. He later became the owner of the Hartsook Inn, a resort in Humboldt County, and two ranches in Southern California on which he reared prized Holstein cattle. Hartsook was married to Bess Hesby, queen of the San Francisco Pan-Pacific Exposition of 1915.