Together, Trump and the Republican National Committee brought in about $18.6 million in May, including another loan from the candidate. Clinton and the Democratic National Committee raised more than double that.
Wealthy Clinton donors also chipped in another $12 million for a super PAC supporting her, while one backing Trump pulled in just over $1 million.
Here are the highlights of the most recent fundraising reports in the 2016 federal elections:
Trump and GOP cash slow
Neither Trump, who on Monday unexpectedly fired his campaign manager, nor his party saw an immediate fundraising boost last month, even though he emerged victorious on May 4 after a primary contest once crowded with 16 opponents.
Donors gave just over $3 million to Trump's campaign. The billionaire businessman lent his effort another $2.2 million, bringing his total outlay over the past year to about $46 million.
The RNC -- which Trump says he is counting on to provide much of his general election operations -- took in about $13 million last month. That's about what it raised in April, without a presidential candidate to generate fundraising enthusiasm.
The party began June with about $20 million in the bank and $7 million in debt. By comparison, four years ago, the RNC began June with about $60 million in the bank. In May 2012, presumptive nominee Mitt Romney and the RNC raised more than $76 million, about quadruple this May's haul.
The figures appear to undercut Trump's comments that money is "pouring in" to the party.
Great America PAC, one of several groups that say they want to help Trump win the White House, took in $1.4 million last month, the most it has raised so far.
One of its top donors was Stanley Hubbard, a Minnesota-based broadcasting executive who decided to back Trump after putting money behind many of his GOP rivals in the primary contest. He gave $25,000. Douglas Kimmelman, an investment manager at Energy Capital Partners, gave $50,000.
The super PAC also benefited from about $83,000 in donated television production by Rapid Response Television, which lists an address in Stafford, Texas.
Most of the other pro-Trump groups were not due to file Monday, having either just formed recently or being subject to a different reporting schedule.
Clinton's campaign raised more than $26 million in May, and she began June with about $42 million cash on hand, her fundraising report shows.
Throughout May, Clinton was embroiled in a primary contest with Vermont Sen. Bernie Sanders, and she spent about $14 million, the May report shows.
For his part, Sanders raised $16.4 million and spent $12.9 million last month. He started June with $9.2 million in cash, which was better than he did in April, when he ended the month with only $5.7 million on hand.
Clinton also had a hand in bringing in money for the DNC in May.
The committee reported raising $12.3 million, but continued to report millions in debt. At the start of this month, the committee reported about $9 million cash on hand, but it also reported $7.9 million in debt.
Additionally, a super PAC helping Clinton's general election effort raised $12 million in May.
Some of that group's biggest contributors include billionaire financier Donald Sussman of New York, who gave $2 million, and Chicago media billionaire Fred Eychaner, who gave $3 million. New York financier Bernard Schwartz contributed $1 million.
Money is beginning to pour in for efforts beyond the presidential race.
On the Republican side, the Freedom Partners Action Fund, a political group led by conservative billionaire industrialists Charles and David Koch, collected $8 million, mostly in large donations, last month. Among the key donors: Charles Koch, who gave $3 million; Wisconsin roofing company executive Diane Hendricks, who gave $2 million; and Virginia developer Richard Gillam, who gave $1 million. Arkansas-based poultry company Mountaire Corporation contributed $2 million.
Freedom Partners is focusing on retaining the Republican Senate majority. The group has already produced ads against Democratic candidates Ted Strickland in Ohio and Russ Feingold in Wisconsin, among others, and began June with almost $14 million in available cash.
Democratic super PACs active in the House and Senate races include House Majority PAC and Senate Majority PAC. Eychaner gave $2 million to each group. Hollywood billionaire Haim Saban gave $1 million to the Senate Majority PAC, which raised a total of $4.7 over the month and had about $11.4 million as of June 1. House Majority PAC raised almost $3 million in May and began this month with just under $12 million in the bank.