Robert Walter "Bob" Kasten Jr. (b. June 19, 1942) is a politician from the state of Wisconsin.

Kasten was born in Milwaukee, Wisconsin and he graduated from the University of Arizona. Kasten was elected to the Wisconsin State Senate in 1972. In 1974, he was elected to the House of Representatives as a Republican. He ran for Governor of Wisconsin in 1978 but he lost the nomination to Lee S. Dreyfus . Kasten ran for the United States Senate in 1980, defeating Senator Gaylord Nelson. Kasten was defeated by Russell Feingold in 1992.