Brian Shortsleeve, a venture capitalist and former MBTA official running for governor as a Republican, raised more than $417,000 last month, a hefty sum that featured thousands in top-dollar donations by business executives from all across the country, according to state data.

The 52-year-old Barnstable Republican touted the May cash haul as the largest of any conservative candidate for governor, challenger, or incumbent in the first filing period following an announcement or declaration of candidacy.

Holly Robichaud, Shortsleeve’s political strategist, said any Republican who hopes to defeat Gov. Maura Healey in next year’s statewide election will “need to do more than just stroke a check.”

“They will need to show broad support from people who believe in them and their message enough to open their own checkbooks to support the cause. Brian’s record-breaking fundraising from people all across the commonwealth demonstrates that he is the only candidate who can take the fight to Healey and win,” Robichaud said in a statement Monday.

Robichaud said former Gov. Charlie Baker, a Republican, set the last fundraising record for the first filing period after a candidacy announcement at $370,000 during his reelection campaign in 2017.

Shortsleeve’s backers ranged from founders of some of the nation’s largest companies to former elected officials in Massachusetts, according to records on file with the Office of Campaign and Political Finance.

The contributions also came from a mix of out-of-state and in-state donors, with dollars also pouring in from Florida, Texas, Louisiana, Vermont, New York, and North Carolina, state data showed.

Shortsleeve, who launched his campaign May 12, drew $1,000 from Niraj Shah, the co-founder of Boston-based Wayfair, an e-commerce company that focuses on furniture and home goods.

Ernie Boch Jr., the local, politically active billionaire who runs Subaru of New England, also handed Shortsleeve $1,000 last month, as did Ray Washburne, the Dallas, Texas-based board chairman of the gas company Sunoco, according to state data.

Scott Brown, the former U.S. senator for Massachusetts who is said to be considering running for office in New Hampshire, donated $1,000 to Shortsleeve, according to state records.

Former Massachusetts Lt. Gov. Kerry Healey, who served with former Gov. Mitt Romney, also gave Shortsleeve $1,000, state data shows.

Brian Dowling, a senior reporter covering Boston courts at Law360 and former Herald reporter, also donated $1,000 to Shortsleeve, according to campaign finance records.

Robichaud, Shortsleeve’s strategist, said the campaign refunded a single $1,000 donation, bringing the total haul from last to $416,000 before expenses.

Fundraising data for Mike Kennealy, a Lexington Republican and former cabinet secretary under Baker, was not immediately available Monday, but a spokesperson for the gubernatorial hopeful slammed Shortsleeve’s numbers.

“No amount of money Brian Shortsleeve raises can erase his failures at the MBTA—or recover the millions wasted on a rail deal with the Chinese Communist Party and an utterly botched Green Line Extension,” the spokesperson, Logan Trupiano, said in a statement.

Healey, who announced plans to run for reelection earlier this year, raised at least $244,000 in May, according to individual deposit reports posted to the state’s campaign finance website. But her cash intake from last month could change when her team files a final report for the month.