The 2006 United States Senate election in California was held November 7, 2006. Incumbent Democratic U.S. Senator Dianne Feinstein won re-election to her third full term. Feinstein stood against Republican Dick Mountjoy, who had never held a statewide elected position, but had been a state senator for several years. Also running was Libertarian Michael Metti, Don Grundmann of the American Independent Party, Todd Chretien of the Green Party and Marsha Feinland of the Peace and Freedom Party. Because California is a state that requires a large amount of money to wage a competitive statewide campaign, it is not unusual - as was the case for this race - for a popular incumbent to have no significant opponent. Several prominent Republicans, such as Bill Jones, Matt Fong, and others, declined to run, and a previously announced challenger, businessman Bill Mundell, withdrew his declaration after determining he would not be a self-funded candidate (as Michael Huffington was in the 1994 election). Since Feinstein's death in 2023, this is the most recent U.S. Senate election in California and latest U.S. Senate election of any state in the nation where both major party Senate nominees are deceased.

Primaries

Link to primary results

Democratic

Green

Others

Candidates

Democratic Party

Lost in primary

Republican Party

American Independent Party

Green Party

Lost in primary

Libertarian Party

Peace and Freedom Party

General election

Controversy

On September 22, the Los Angeles Times reported that Mountjoy's official biography, as found on his campaign website, falsely asserted that he had served aboard the battleship USS Missouri during the Korean War—he had actually served aboard the heavy cruiser USS Bremerton. A review of the ships' logs corroborated this and the website was quickly changed to reflect his service aboard the Bremerton rather than the Missouri. "I think it was just something that somebody picked up, it didn't come from me."

Predictions

Polling

Results

Feinstein won the election easily. She won almost every major populated area, winning in Los Angeles, San Francisco, Sacramento, and San Diego. Feinstein was projected the winner as soon as the polls closed at 11 P.M. EST.

Results breakdown

Final results from the Secretary of State of California.

Counties that flipped from Republican to Democratic

Counties that flipped from Democratic to Republican