David E. Cox (February 20, 1938 – July 13, 2010) was an American politician from Holdenville, Oklahoma.

A Republican, he served as a California State Senator, representing the 1st district from December 2004 until his death in July 2010, and also served as a California State Assemblyman for the six years immediately before his Senate tenure, including three years as Assembly Republican Leader.

In 2004, Cox successfully ran again for the state Senate, this time in the 1st district.

His district included all or portions of Alpine, Amador, Calaveras, El Dorado, Lassen, Placer, Plumas, Modoc, Mono, Nevada, Sacramento and Sierra Counties.

Cox died in office on July 13, 2010, following a thirteen-year-long battle with prostate cancer.