WASHINGTON — When Donald J. Trump strides onto the inaugural ballroom floor this week amid the sprawling celebration of his swearing-in, he will have corporate America and many of its titans to thank for the rapturous greeting.

Chevron, the oil giant, has given $500,000 for the dayslong festivities. Boeing, which has been a target of Mr. Trump, pledged $1 million. And Sheldon and Miriam Adelson, giants of the gambling industry, are said to have donated more than that by themselves.

They are far from alone.

All told, the group planning the inaugural festivities says it has raised more than $100 million, which would be nearly double the record for an inauguration, with much of it coming in six- and seven-figure checks from America’s corporate suites.

In exchange, Mr. Trump’s most prolific donors will gain access to what amounts to a parallel inauguration week, carefully planned and largely out of public sight, during which they can mingle with members of the incoming administration over intimate meals and witness Mr. Trump’s ascension from the front rows.