Booth Gardner (born August 21, 1936) was the 19th Governor of the U.S state of Washington between 1985 and 1993. He also served as the ambassador of the GATT. He is a Democrat. Before serving as governor, Gardner was Pierce County Executive. His service was notable for advancing standards-based education and environmental protection.

Gardner is an heir to the Weyerhaeuser fortune. His stepfather is Norton Clapp, one of the original owners of the Seattle Space Needle. In 1976, he owned the Tacoma Tides in its one year in the American Soccer League. In 1978 he co-owned the Colorado Caribous franchise in the NASL with Jim Guercio.

In 1994, one year after his retirement, Gardner was diagnosed with Parkinson's Disease. In 2006 he announced his support for assisted suicide. In 2008 he filed and successfully spearheaded the campaign for Initiative 1000, Washington's Death With Dignity Act, which was closely modeled on Oregon's assisted dying law,; he remains involved in implementing the Act. Gardner has said that he supports going even further than the current Washington and Oregon laws, to eventually permit lethal prescriptions for people whose suffering is unbearable without the requirement that the sufferer have a terminal condition.
In 2009, The Last Campaign of Governor Booth Gardner, a short documentary film, was produced by Just Media and HBO, chronicling the Initiative 1000 campaign. The film was nominated for an Academy Award for Best Documentary Short.
 
Gardner supported eliminating Washington's WASL test, a standardized test that was required to graduate high school, it was replaced in 2009 by the MSP for grades three through eight and the HSPE for grades eight through twelve.