William Freeman Vilas (July 9, 1840 – August 27, 1908) was an American lawyer, politician, and United States Senator.

[1] As a prominent Bourbon Democrat, he was also a member of the cabinet of U.S. President Grover Cleveland, serving as the 33rd Postmaster General and the 17th Secretary of the Interior.

Vilas served as a member of the Wisconsin State Assembly in 1885, until he was appointed the Postmaster General between 1885 and 1888, and as Secretary of the Interior from 1888 to 1889, both under President Grover Cleveland.

[4] After leaving the cabinet, he led Wisconsin German Americans in the protest against the Bennett Law of 1889 which required schools to only use the English language.

He then became one of the chief organizers of the National Democratic Party, attended the convention at Indianapolis, and was chairman of its committee on resolutions.

His family donated land to the city of Madison to build a public park, which later became a part of the Henry Vilas Zoo.