Elon Musk, the world’s richest man, spent over a quarter of a billion dollars in the final months of this year’s election to help Donald J. Trump win the presidency, federal filings revealed on Thursday.

The sum is a fraction of Mr. Musk’s wealth. But it is nonetheless a staggering amount from a single donor, who poured the cash into allied groups and is now playing a role in helping shape the next administration.

One of Mr. Musk’s most brazen moves — which emerged only on Thursday — was spending $20 million to prop up a super PAC that was named after Ruth Bader Ginsburg, the late liberal Supreme Court justice, but that sought to help Mr. Trump by softening his anti-abortion positions.

Mr. Musk put the lion’s share of the money he donated toward his main super PAC, America PAC, cutting three checks for $25 million each in the final weeks of the race, according to the new filings with the Federal Election Commission. Mr. Musk also spent $40.5 million on legally controversial checks to voters in swing states who signed a petition in support of the Constitution.

Over the course of the race, he gave America PAC a staggering $239 million in both cash and in-kind contributions.

America PAC conducted what it described as an expansive ground-game effort on Mr. Trump’s behalf. Mr. Musk came to see defeating President Biden as a vital imperative and swung hard toward Mr. Trump after the assassination attempt against him in July. He became so invested in the effort that he campaigned frequently for the Republican nominee in Pennsylvania, widely seen as the most important battleground state.

Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.

Thank you for your patience while we verify access.

Already a subscriber? Log in.

Want all of The Times? Subscribe.