Knollenberg was born in Mattoon, Illinois and graduated from Eastern Illinois University in 1955. After graduation, he served in the United States Army from 1955 to 1957. He became an insurance agent and moved to Oakland County, Michigan in 1967.

In 1992, Knollenberg was elected as a Republican to the United States House of Representatives for the 103rd Congress and to the six succeeding Congresses, serving from January 3, 1993 to the present. He replaced William Broomfield, who was not a candidate for reelection. Knollenberg has supported NAFTA and President George W. Bush's steel tariffs, although he did ask for a review of the tariffs after hearing of price increases. Knollenberg was reelected to his seventh term in 2004. Despite being a seven term incumbent and outspending his Democratic opponent by a ratio of 10:1 he only garnered 58f the vote in his district.

Knollenberg is on the United States House Committee on Appropriations. He serves as the Chairman on U.S. House Appropriations Subcommittee on Transportation, Treasury, and Housing and Urban Development, The Judiciary, District of Columbia. He also is on the sub-committee on Foreign Operations, Export Financing and Related Programs.

Knollenberg faces a primary challenger, Particia Godchaux for re-election in 2006.democratic candidate Nancy Skinner, a former radio-talk show host, is the party's nominee for the 9th district.. Dawn Aumanne of the Green Party is the only third party canidate in the race.

This article incorporates facts obtained from the public domain Biographical Directory of the United States Congress.