Elwood Haynes "Bud" Hillis (March 6, 1926 – January 4, 2023) was an American politician and lawyer from Indiana.

He was a Republican member of the United States House of Representatives, serving Indiana's 5th congressional district for 8 terms from 1971 to 1987.

Their father, Glen R. Hillis, was the Republican nominee for Governor of Indiana in 1940, losing by less than 4,000 votes.

Hillis served as a member of the Indiana House of Representatives, Ninety-fifth and Ninety-sixth General Assemblies.

This article incorporates public domain material from the Biographical Directory of the United States Congress