In a head-to-head matchup, Biden leads Trump by 49% to 40%, which is outside the poll’s margin of sampling error.
The margin is basically unchanged since the last Fox News poll, which was conducted in February, when Biden led Trump 49% to 41%.
Besides gaining support from liberals, non-whites and moderates, Biden bested Trump in two categories critical to his re-election: suburban women and voters ages 65 and older.
Trump largely won the support of conservatives, white men, and whites without a college degree, as well as white evangelical Christians and those who regularly attend religious services.
A majority of voters polled also approved of Biden's promise to pick a female running-mate.
Adding diversity to the Democratic ticket is widely seen as a priority for a party that now has two white men, both in their late 70s, as its last two primary candidates.
During the last Democratic debate, Biden said: "My administration will look like the country and I commit that I will in fact pick a woman to be vice president. There are a number of women who are qualified to be president tomorrow. I will pick a woman as my vice president."
About 63% in the Fox News poll approved of this promise, while 20% disapproved, and 17% were unsure.
There was no gender gap with this question, but those under the age 45 were 10 points more likely to approve.
Trump's approval rating, according to this poll, was 48% compared with 51% who disapprove.
According to Fox News, the poll was conducted from March 21-24, 2020 under the joint direction of Beacon Research (D) and Shaw & Company (R), and included interviews with 1,011 randomly chosen registered voters nationwide. The poll has a margin of a sampling error of plus or minus 3 percentage points.
This article originally appeared on USA TODAY: Joe Biden leads Trump by nine points in latest Fox News poll