The campaign said it had received more than 3,000 contributions since Dean formally entered the race in March, with all but 3 percent coming from within the state.
"We're going to be able to mount a very serious, strong campaign," Dean said in a phone interview.
About four in five donations being made online, and a majority of those online contributions were for $25 or less.
"Any contribution, no matter what the amount, is deeply appreciated," Dean said. "But I think it's good to show a broad base of support in all sizes of contributions from all over Tennessee."
Dean is unopposed so far in his pursuit of the Democratic nomination, but state House Minority Leader Craig Fitzhugh is seriously considering entering the race. Dean said he follow his plan for the race regardless of which opposition he draws.
"That's totally out of my control," he said.
The former mayor's campaign noted that Dean's haul is the largest in a single fundraising for a Tennessee Democrat making a statewide bid in more than a decade.
Democrat Mike McWherter, who lost the 2010 governor's race to Republican Bill Haslam, spent about $3.4 million on his campaign, with about half coming in the form of personal loans. Haslam spent $16.7 million on the primary and general election that year, including $3.5 million of his own money
Democrats haven't won an open race for statewide office since Phil Bredesen's election as governor in 2002, but Dean said he has history on his side: The governor's office has switched between Democrats and Republicans every eight years since the state began allowing consecutive terms in the 1970s.
"I start from the premise that Tennesseans want a governor who's in the middle of the road, who's pragmatic, has common sense, and has got experience," Dean said.
"My time as mayor certainly gives me more executive experience in government than other candidates," he said. "And the issues we're talking about — education, job creation and health care — are the issues people care about."
Dean said he's undaunted by the fundraising prowess of Republicans such as businessmen Randy Boyd of Knoxville and Bill Lee of Franklin. Both have announced that their first major fundraisers netted more than the $1.2 million Dean collected through the whole period.
Lee, Boyd and state Sen. Mae Beavers of Mt. Juliet have not yet divulged fundraising totals for their Republican gubernatorial bids. Other potential GOP candidates include U.S. Rep. Diane Black of Gallatin and state House Speaker Beth Harwell of Nashville.
Dean wouldn't rule out directing family wealth into his campaign — but not quite yet.
"Obviously I'm committed to the race, but right now we're raising money and getting good, widespread support," he said.