The poll also found that a majority of Californians believe President Donald Trump is more interested in what's best for himself than what's best for America.
The survey was released as Comey gave historic testimony to Congress, admitting for the first time that the FBI has been investigating the Trump campaign's relationship with Russian officials since July.
Comey said it appears Russian President Vladimir Putin was motivated to interfere in the election by his dislike for Hillary Clinton, who supported Putin's opponents when she was serving as secretary of state.
Comey also said the FBI has no information to support Trump's tweeted allegations that former President Barack Obama had Trump Tower wiretapped during the campaign.
The SurveyUSA poll talked to 573 adult Californians who say they pay attention to current events. The poll had a margin of error around plus/minus 4 percent.
Of those surveyed, 62 percent said they had confidence in the FBI, with 18 percent expressing no confidence and 20 percent not sure. When asked if they believe Comey is biased, 25 percent said he is in favor of Republicans, 16 percent said he favors Democrats and 30 percent believe he is unbiased.
About 44 percent of poll respondents said they believe Comey is interested in what's best for America, while 30 percent said Comey is interested in what's best for himself.
When asked that same question about Trump, 38 percent said the president is interested in what's best for America and 56 percent said he is interested in what's best for Donald Trump.
Poll respondents also said they were concerned about possible Russian influence on the 2016 presidential election, with 40 percent describing themselves as "very" concerned and 23 percent "somewhat" concerned.
And when asked about Trump's 2016 election victory, 38 percent said he won "fair and square" while 43 percent said he was "helped across the finish line."