William Thompson (26 November 1816 - 19 October 1897) was an English born viticulturist, credited with the introduction and popularization of the Sultana grape in the Central Valley of California.
Known widely as the Thompson Seedless variety in the United States, the high yielding pale green grape accounts for approximately 95% of raisins produced in California.
Thompson emigrated to the United States and after a period living in Illinois settled with his family in Sutter, California in 1863.
In 1872 he acquired cuttings of the Lady de Coverly (sultana) grape from the Elwanger & Barry Nursery of Rochester, New York.
[1] After grafting the cuttings onto existing rootstock, Thompson was eventually successful in 1875 of producing a crop of 50 pounds of large sweet, thin skinned seedless grapes.