Franklin Knight Lane (July 15, 1864 – May 18, 1921) was an American progressive politician from California. A member of the Democratic Party, he served as United States Secretary of the Interior from 1913 to 1920. He also served as a commissioner of the Interstate Commerce Commission, and was the Democratic nominee for Governor of California in 1902, losing a narrow race in what was then a heavily Republican state.

Lane was born July 15, 1864, near Charlottetown, Prince Edward Island, in what was then a British colony but is now part of Canada, and in 1871, his family moved to California. After attending the University of California while working part-time as a reporter, Lane became a New York correspondent for the San Francisco Chronicle, and later became editor and part owner of a newspaper. Elected City Attorney of San Francisco in 1898, a post he held for five years, Lane ran in 1902 for governor and in 1903 for mayor of San Francisco, losing both races. In 1903, he received the support of the Democratic minority in the California State Legislature during the legislature's vote to elect a United States Senator from California.

Appointed a commissioner of the Interstate Commerce Commission by U.S. President Theodore Roosevelt in 1905 and confirmed by the Senate the following year, Lane was reappointed in 1909 by President William Howard Taft. His fellow commissioners elected him as chairman in January 1913. The following month, Lane accepted President-elect Woodrow Wilson's nomination to become Secretary of the Interior, a position in which he served almost seven years until his resignation in early 1920. Lane's record on conservation was mixed: he supported the controversial Hetch Hetchy Reservoir project in Yosemite National Park, which flooded a valley esteemed by many conservationists, but also presided over the establishment of the National Park Service.

The former Secretary died of heart disease at the Mayo Clinic in Rochester, Minnesota, on May 18, 1921. Because of two decades of poorly paid government service, and the expenses of his final illness, he left no estate, and a public fund was established to support his widow. Newspapers reported that had he not been born in what is now Canada, he would have become president. In spite of that limitation, Lane was offered support for the Democratic nomination for vice president, though he was constitutionally ineligible for that office as well.