"I am not a candidate," said Feinstein, who appeared with Davis at ceremonies to open a rail extension to San Francisco International Airport.
Feinstein, the Democratic nominee for governor in 1990, had been considered the strongest potential Democratic candidate. But party officials have long been urging prominent Democrats to stay off the ballot, insisting the governor should be allowed to stave off the recall without facing challengers from his own party.
Other high-level California Democrats, including Lt. Gov. Cruz Bustamante and Attorney General Bill Lockyer, had already said they had no intention of running.
Recall supporters claim to have gathered about 800,000 signatures in favor forcing an election to recall Davis, who won a second term in November.
Recall proponents have until Sept. 2 to collect nearly 900,000 signatures. They want to submit the needed signatures next month, which would force a special election this fall.
Potential Republican candidates include Rep. Darrell Issa, who is largely bankrolling the recall effort; Bill Simon, who lost to Davis in last year's election, and actor Arnold Schwarzenegger (search).
Feinstein said Davis, whose approval numbers have plummeted as the state struggles with a huge budget deficit, was re-elected as governor "just six months ago," and should not have to mount a new campaign to keep his job.
"The recall is really there for gross moral turpitude, corruption, or some extraneous terrible circumstance in which you have to remove somebody from office," Feinstein said. "Now the state's having a rough time. So is every other state in the union right now."
Feinstein, a former mayor of San Francisco, was first elected to the Senate in 1992. Her current term expires in 2006.